{"title":"Window Glass — Replacement Sealed Units","description":"\u003cstyle\u003e\n  .pr-cwg { max-width: 1140px; margin: 0 auto; padding: 0 16px; color: var(--pr-text, #1f2933); font-family: var(--pr-font-body, inherit); }\n  .pr-cwg * { box-sizing: border-box; }\n  .pr-cwg__hero { padding: 28px 0 12px; }\n  .pr-cwg__hero h2 { font-size: 26px; margin: 0 0 10px; color: var(--pr-text, #1f2933); font-family: var(--pr-font-heading, inherit); }\n  .pr-cwg__hero p { font-size: 17px; line-height: 1.6; margin: 0 0 12px; color: var(--pr-text-body, #1f2933); }\n  .pr-cwg__hero strong { color: var(--pr-text, #1f2933); }\n  .pr-cwg__personas { display: grid; grid-template-columns: 1fr; gap: 16px; padding: 12px 0 28px; }\n  @media (min-width: 720px) { .pr-cwg__personas { grid-template-columns: 1fr 1fr; } }\n  .pr-cwg__persona { border: 1px solid var(--pr-border-light, #e5e7eb); border-radius: var(--pr-radius-lg, 14px); padding: 24px; background: var(--pr-bg-white, #fff); box-shadow: var(--pr-shadow-sm, 0 1px 2px rgba(0,0,0,0.04)); 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gap: 8px; }\n  .pr-cwg__chip { display: inline-block; padding: 8px 14px; background: var(--pr-bg-light, #f9fafb); border: 1px solid var(--pr-border-light, #e5e7eb); border-radius: var(--pr-radius-full, 999px); color: var(--pr-text, #1f2933); text-decoration: none; font-size: 13px; font-weight: 500; transition: background 0.15s, border-color 0.15s; }\n  .pr-cwg__chip:hover { background: var(--pr-bg-white, #fff); border-color: var(--pr-accent, #D98E04); color: var(--pr-accent, #D98E04); }\n  .pr-cwg__sticky-cta { margin: 12px 0 36px; padding: 20px 24px; background: var(--pr-text, #1f2933); color: #fff; border-radius: var(--pr-radius-lg, 14px); display: grid; grid-template-columns: 1fr; gap: 12px; align-items: center; }\n  @media (min-width: 720px) { .pr-cwg__sticky-cta { grid-template-columns: 1fr auto; } }\n  .pr-cwg__sticky-cta h3 { margin: 0 0 4px; font-size: 17px; color: #fff; }\n  .pr-cwg__sticky-cta p { margin: 0; font-size: 14px; line-height: 1.5; color: #e5e7eb; }\n  .pr-cwg__sticky-cta a { color: var(--pr-accent, #D98E04); font-weight: 600; text-decoration: none; }\n  .pr-cwg__sticky-cta a:hover { text-decoration: underline; }\n  .pr-cwg__sticky-cta .pr-cwg__btn { background: var(--pr-accent, #D98E04); color: #fff; align-self: stretch; text-align: center; }\n\u003c\/style\u003e\n\n\u003cdiv class=\"pr-cwg\"\u003e\n\n  \u003csection class=\"pr-cwg__hero\"\u003e\n    \u003ch2\u003eReplacement window glass — sealed units made to your sizes\u003c\/h2\u003e\n    \u003cp\u003e\u003cstrong\u003eMisted between the panes? Cracked? Failing to keep the heat in?\u003c\/strong\u003e In most cases you don't need a whole new window — just a new sealed unit. Pane Relief manufactures replacement double-glazed, triple-glazed, low-E (A-rated), acoustic, toughened, laminated, obscure, and Georgian-bar sealed units to fit casement, sash, bay, tilt-and-turn, fixed-light, and conservation windows. Pick the window type below to see real prices and lead times — or use the configurator if your spec or size is non-standard.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__personas\"\u003e\n    \u003cdiv class=\"pr-cwg__persona\"\u003e\n      \u003cspan class=\"pr-cwg__persona-tag\"\u003eHomeowner\u003c\/span\u003e\n      \u003ch3\u003eReplacing your own window glass\u003c\/h3\u003e\n      \u003cp\u003eFree UK mainland delivery on every order. 10-year manufacturer warranty on edge-seal integrity. FENSA-registered fitter recommendations in your postcode. Phone helpline (08:00-18:00 Mon-Fri) for sanity-checking your measurements before you order. Most stock-size units ship in 5-7 working days.\u003c\/p\u003e\n      \u003ca class=\"pr-cwg__btn\" href=\"\/pages\/configure\"\u003eConfigure my unit\u003c\/a\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"pr-cwg__persona\"\u003e\n      \u003cspan class=\"pr-cwg__persona-tag\"\u003eTrade\u003c\/span\u003e\n      \u003ch3\u003eInstaller, builder, glazier\u003c\/h3\u003e\n      \u003cp\u003eNet 30 trade accounts, tiered volume discount on 5+\/20+\/50+ unit orders, scheduled site delivery, priority dispatch for FENSA installers and developers. Every unit ships UKCA-marked with BS EN 1279 compliance; Declaration of Performance on request. Bespoke quotes via the trade portal.\u003c\/p\u003e\n      \u003ca class=\"pr-cwg__btn pr-cwg__btn--ghost\" href=\"\/pages\/bulk-orders\"\u003eTrade pricing \u0026amp; bulk orders\u003c\/a\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__section\"\u003e\n    \u003ch2\u003eWhich window type are you replacing?\u003c\/h2\u003e\n    \u003cp class=\"pr-cwg__lede\"\u003eSix common window scenarios. Pick the closest match — each links to the relevant flagship product or filtered range.\u003c\/p\u003e\n    \u003cdiv class=\"pr-cwg__finder\"\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/casement-window-glass-replacement\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003cpath d=\"M12 2.69l5.66 5.66a8 8 0 11-11.31 0L12 2.69z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eStandard casement\u003c\/h3\u003e\n        \u003cp\u003eUPVC, timber, or aluminium casements. Most common UK type — 24mm or 28mm rectangular sealed units.\u003c\/p\u003e\n      \u003c\/a\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/bay-window-glass-replacement\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003cpath d=\"M3 9l9-7 9 7v11a2 2 0 01-2 2H5a2 2 0 01-2-2V9z\"\u003e\u003c\/path\u003e\u003cpath d=\"M9 22V12h6v10\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eBay window\u003c\/h3\u003e\n        \u003cp\u003e3-pane, 4-pane, or 5-pane bay configurations. Angled or square. We supply matching units across all lights.\u003c\/p\u003e\n      \u003c\/a\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/sash-window-glass-replacement\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003cpath d=\"M21 16V8a2 2 0 00-1-1.73l-7-4a2 2 0 00-2 0l-7 4A2 2 0 003 8v8a2 2 0 001 1.73l7 4a2 2 0 002 0l7-4A2 2 0 0021 16z\"\u003e\u003c\/path\u003e\u003cpath d=\"M3.27 6.96L12 12.01l8.73-5.05M12 22.08V12\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eSash window\u003c\/h3\u003e\n        \u003cp\u003eVertical sliding sash. Slim 14mm Histoglass-equivalent for conservation areas. Listed-building friendly options.\u003c\/p\u003e\n      \u003c\/a\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/tilt-turn-window-glass\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003ccircle cx=\"12\" cy=\"12\" r=\"10\"\u003e\u003c\/circle\u003e\u003cpath d=\"M4.93 4.93l14.14 14.14\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eTilt \u0026amp; turn\u003c\/h3\u003e\n        \u003cp\u003eContinental-style inward-opening. Often larger panes — toughened recommended on units over 1m².\u003c\/p\u003e\n      \u003c\/a\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/bedroom-window-glass\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003cpath d=\"M18 10h-1.26A8 8 0 109 20h9a5 5 0 000-10z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eBedroom window\u003c\/h3\u003e\n        \u003cp\u003eAcoustic and thermal options. Laminated acoustic interlayer cuts road and aircraft noise by up to 44 dB Rw.\u003c\/p\u003e\n      \u003c\/a\u003e\n      \u003ca class=\"pr-cwg__tile\" href=\"\/products\/bathroom-obscure-glass\"\u003e\n        \u003cspan class=\"pr-cwg__tile-icon\" aria-hidden=\"true\"\u003e\u003csvg width=\"28\" height=\"28\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.5\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\"\u003e\u003cpath d=\"M12 2.69l5.66 5.66a8 8 0 11-11.31 0L12 2.69z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\n        \u003ch3\u003eBathroom (obscure)\u003c\/h3\u003e\n        \u003cp\u003ePrivacy-rated obscure glass — Levels 1-5 (Pilkington Texture range). Toughened required for shower-screen height.\u003c\/p\u003e\n      \u003c\/a\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__section pr-cwg__measure\"\u003e\n    \u003ch2\u003eMeasure twice, order once\u003c\/h2\u003e\n    \u003cp class=\"pr-cwg__lede\"\u003eFor windows the measure is the same as for doors: measure the rebate, not the frame opening. We need the sealed-unit size, not the daylight opening.\u003c\/p\u003e\n    \u003cdiv class=\"pr-cwg__info\"\u003e\n      \u003cdiv class=\"pr-cwg__info-card\"\u003e\n        \u003ch3\u003eThe 5-step measure\u003c\/h3\u003e\n        \u003col\u003e\n          \u003cli\u003eOpen the window or carefully remove a glazing bead. Measure visible glass width at top, middle, and bottom — use the smallest number.\u003c\/li\u003e\n          \u003cli\u003eMeasure visible glass height at left, middle, and right — use the smallest number.\u003c\/li\u003e\n          \u003cli\u003eAdd 6mm to both dimensions (3mm clearance into each side of the rebate).\u003c\/li\u003e\n          \u003cli\u003eMeasure the overall sealed-unit thickness with vernier callipers (typical: 24mm, 28mm, or 36mm).\u003c\/li\u003e\n          \u003cli\u003ePhotograph the frame profile, the rebate depth, and any kitemark stamp on the existing glass. Send to our team for a free spec-match if you're unsure.\u003c\/li\u003e\n        \u003c\/ol\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"pr-cwg__info-card\"\u003e\n        \u003ch3\u003ePricing transparency\u003c\/h3\u003e\n        \u003cp\u003ePrices shown on this collection are \u003cstrong\u003e\"From £X\"\u003c\/strong\u003e — the smallest stock size at base specification (4mm-20mm-4mm argon-filled annealed). Custom sizes, toughened or laminated safety, low-E coatings (Planitherm, Optitherm), acoustic interlayers (PVB acoustic), obscure patterns, Georgian bars, or oversized panels are all priced live in the configurator.\u003c\/p\u003e\n        \u003cp\u003e\u003ca href=\"\/pages\/configure\"\u003eOpen the configurator →\u003c\/a\u003e\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__faq\"\u003e\n    \u003ch2\u003eWindow glass — common questions answered\u003c\/h2\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: My window is misted between the panes. Do I need a whole new window?\u003c\/h3\u003e\n      \u003cp\u003eNo — almost never. Misting between the panes means the \u003cstrong\u003eedge-seal on the sealed unit has failed\u003c\/strong\u003e and moisture has migrated into the air gap. The frame, hinges, locks, and gaskets are usually fine. You just need a new sealed unit fitted into the existing frame. That's typically 60-80% cheaper than a full window replacement. If the frame itself is rotten, twisted, or has failed locks then yes — replace the whole window. Send a photo on the helpline for a free diagnosis.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: What's the difference between a sash window measure and a casement measure?\u003c\/h3\u003e\n      \u003cp\u003eBoth are measured at the rebate, but on sash windows the glass typically sits in \u003cstrong\u003eputty (timber sashes) or a slim bead (modern UPVC sashes)\u003c\/strong\u003e rather than a deep gasketed rebate. The rule of thumb: ease back the putty fillet or pop a bead, measure visible glass plus 3mm of overlap each side. Listed sashes often require slim-profile units (14mm overall, Krypton-filled) to retain the timber muntin proportions — those are a separate stock line; ask via the helpline.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: Is low-E worth paying for?\u003c\/h3\u003e\n      \u003cp\u003eYes — for any window receiving long daylight hours. A low-E soft-coat unit (Planitherm Total+, Optitherm S3) drops the U-value from around 2.8 W\/m²K (standard double-glazed) to \u003cstrong\u003e1.2-1.4 W\/m²K\u003c\/strong\u003e. On a typical 3-bed UK semi that's a quantifiable drop in heating bills (typically £80-£140\/year per window, depending on orientation). All our stock units use a low-E coating by default unless you opt out; the price difference is small and the payback is fast.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: U-value vs g-value — what do they mean and which matters more?\u003c\/h3\u003e\n      \u003cp\u003e\u003cstrong\u003eU-value\u003c\/strong\u003e (W\/m²K) measures heat loss out — lower is better. \u003cstrong\u003eg-value\u003c\/strong\u003e (also called solar factor) measures solar heat gain in — higher is better in winter but worse in summer. For most UK homes a unit with low U-value (~1.2) and mid g-value (~0.5) is the right balance. South-facing rooms that overheat in summer can benefit from a solar-control coating (lower g-value, around 0.3) — but those rooms are rare in the UK climate, so don't over-spec by default.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: A-rated vs C-rated — what's the difference?\u003c\/h3\u003e\n      \u003cp\u003eBFRC (British Fenestration Rating Council) ratings A++ to E represent the \u003cstrong\u003enet energy efficiency\u003c\/strong\u003e of a complete window assembly — frame plus glass. Sealed units alone don't get a BFRC rating; the assembly does. For a fair like-for-like, our stock low-E units typically push the existing frame from C-rated to A or A+ once retrofitted. If you're targeting a specific rating for a planning condition or new-build SAP submission, tell us the target — we'll spec the right glass build-up.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: I get condensation on the inside of the window. Is the glass failing?\u003c\/h3\u003e\n      \u003cp\u003eAlmost never — internal condensation is a \u003cstrong\u003ehumidity and ventilation problem\u003c\/strong\u003e, not a glass problem. It happens when warm moist indoor air contacts a cold internal glass surface. Fix: more trickle-vent airflow, run extractor fans during cooking and showering, dry laundry outside. Upgrading to a low-E unit raises the internal glass surface temperature and reduces (but doesn't eliminate) condensation. \u003cstrong\u003eMisting between the panes\u003c\/strong\u003e (inside the sealed unit, where you can't wipe it off) is a different problem — that's a failed edge-seal and the unit needs replacing.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: I'm in a Conservation Area \/ listed building — what are my options?\u003c\/h3\u003e\n      \u003cp\u003eConservation and listed properties typically require \u003cstrong\u003eslim-profile units\u003c\/strong\u003e (10mm-14mm overall thickness) to retain the original timber muntin proportions and external sightlines. We stock Krypton-filled slim units (Histoglass-equivalent) that hit U-values around 1.6 W\/m²K — a meaningful upgrade on single glazing while satisfying most planning officers. Confirm with your local conservation officer first; we'll supply a spec-sheet for their approval before you order.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: Is safety glass required for window glass?\u003c\/h3\u003e\n      \u003cp\u003eSometimes. Approved Document N and BS 6262-4 mandate impact-resistant glazing (toughened BS EN 12150 or laminated BS EN 14449) in any pane that sits \u003cstrong\u003ebelow 800mm from floor level\u003c\/strong\u003e, or near a door. Bathroom windows, low-cill bedroom windows, and floor-to-ceiling glazing all typically require safety glass. The configurator highlights critical-location panels automatically once you enter the dimensions and cill height.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: Acoustic glass — does it really work?\u003c\/h3\u003e\n      \u003cp\u003eYes, for the right frequencies. A standard double-glazed unit gets you to about 28-30 dB Rw acoustic insulation. A laminated acoustic unit (with PVB acoustic interlayer) jumps to \u003cstrong\u003e38-44 dB Rw\u003c\/strong\u003e — a noticeable, measurable improvement on busy roads, near flightpaths, or in railway corridors. If you're not sure whether acoustic glass is worth the upgrade for your situation, read the \u003ca href=\"\/pages\/acoustic-glass\"\u003eacoustic glass guide\u003c\/a\u003e — it shows the dB drops by traffic type.\u003c\/p\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"pr-cwg__faq-item\"\u003e\n      \u003ch3\u003eQ: What's the warranty and lead time?\u003c\/h3\u003e\n      \u003cp\u003e10-year manufacturer warranty on edge-seal integrity (BS EN 1279-2 weathered durability), 5-year on coatings. Stock-size units: 5-7 working days. Custom rectangular non-stock: 7-10 working days. Shaped, arched, or oversized (any dimension \u0026gt;1500mm): 10-14 working days. Toughened or laminated specs add 2-3 working days. Mis-measurements remade at cost (materials only).\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__crosslinks\"\u003e\n    \u003ch2\u003eRelated guides and specifications\u003c\/h2\u003e\n    \u003cdiv class=\"pr-cwg__chip-row\"\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/safety-security-glass\"\u003eSafety \u0026amp; security glass\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/energy-rated-glass-units\"\u003eEnergy-rated units (A\/B\/C)\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/acoustic-glass\"\u003eAcoustic glass guide\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/collections\/door-glass-units\"\u003eDoor glass units\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/collections\/conservatory-glass\"\u003eConservatory glass\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/configure\"\u003eGlass configurator\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/bulk-orders\"\u003eTrade \u0026amp; bulk orders\u003c\/a\u003e\n      \u003ca class=\"pr-cwg__chip\" href=\"\/pages\/contact-us\"\u003eContact us\u003c\/a\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"pr-cwg__sticky-cta\"\u003e\n    \u003cdiv\u003e\n      \u003ch3\u003eNeed help choosing the right window glass?\u003c\/h3\u003e\n      \u003cp\u003eCall the helpline on \u003ca href=\"tel:01173303057\"\u003e0117 330 3057\u003c\/a\u003e (08:00-18:00 Mon-Fri), or \u003ca href=\"\/pages\/contact-us\"\u003erequest a quote\u003c\/a\u003e. Trade accounts unlock live tier pricing and Net 30 terms.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003ca class=\"pr-cwg__btn\" href=\"\/pages\/configure\"\u003eConfigure my window glass\u003c\/a\u003e\n  \u003c\/section\u003e\n\n\u003c\/div\u003e\n","products":[{"product_id":"double-glazed-unit-4mm-basic-unit","title":"Standard Double-Glazed Unit","description":"\u003ch2\u003eStandard Double-Glazed Unit — Clear Float, Budget-Friendly\u003c\/h2\u003e\u003cp\u003eOur \u003cstrong\u003eStandard Double-Glazed Unit\u003c\/strong\u003e is a straightforward, no-frills sealed unit built from two panes of \u003cstrong\u003e4mm clear float glass\u003c\/strong\u003e with a \u003cstrong\u003e16mm air-filled cavity\u003c\/strong\u003e. At a U-value of \u003cstrong\u003e2.8 W\/m²K\u003c\/strong\u003e, this unit won't meet current Part L requirements for heated living spaces — but that's not what it's designed for.\u003c\/p\u003e\u003cp\u003eThis is the right unit for \u003cstrong\u003egarages, outbuildings, workshops, sheds, greenhouses, and non-heated spaces\u003c\/strong\u003e where you need double glazing for weather protection and security but don't need energy-rated performance. It's also widely used for \u003cstrong\u003esecondary glazing\u003c\/strong\u003e installations and internal partitions.\u003c\/p\u003e\u003ch2\u003eWhen to Choose Standard Clear\/Clear\u003c\/h2\u003e\u003cp\u003eIf your project doesn't fall under Building Regulations Part L (non-heated spaces, like-for-like replacements in some circumstances, or agricultural buildings), this unit saves significant cost compared to Low-E argon alternatives. For heated rooms requiring Building Control sign-off, choose our Low-E Argon IGU instead.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eU-value:\u003c\/strong\u003e 2.8 W\/m²K (air filled) or 2.6 W\/m²K (argon upgrade available)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfiguration:\u003c\/strong\u003e 4mm clear + 16mm air + 4mm clear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight transmittance:\u003c\/strong\u003e ~80% — maximum daylight\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall thickness:\u003c\/strong\u003e 24mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eManufactured to \u003cstrong\u003eBS EN 1279\u003c\/strong\u003e at our Bristol facility with the same quality control as our premium range. Nationwide delivery available. \u003cstrong\u003e10-year warranty\u003c\/strong\u003e on seal integrity.\u003c\/p\u003e\u003cp\u003eUse our \u003cstrong\u003eglass configurator\u003c\/strong\u003e to get an instant price for your exact dimensions.\u003c\/p\u003e","brand":"Pane Relief","offers":[{"title":"Compact","offer_id":60899495018826,"sku":"TG-COMPACT-MTM","price":200.0,"currency_code":"GBP","in_stock":true},{"title":"Standard","offer_id":60899495051594,"sku":"TG-STANDARD-MTM","price":500.0,"currency_code":"GBP","in_stock":true},{"title":"Large","offer_id":60899495084362,"sku":"TG-LARGE-MTM","price":1200.0,"currency_code":"GBP","in_stock":true},{"title":"Extra Large","offer_id":60899495117130,"sku":"TG-XL-MTM","price":2500.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_96471dcc-30fb-47d4-90f5-97802e8d8dac.webp?v=1773249496"},{"product_id":"double-glazed-unit-1000-800-mm","title":"Double Glazed Unit – 1000 × 800 mm","description":"\u003ch2\u003eDouble Glazed Unit — 1000 × 800mm Ready-to-Fit\u003c\/h2\u003e\u003cp\u003eThis \u003cstrong\u003e1000 × 800mm double-glazed sealed unit\u003c\/strong\u003e is a ready-to-fit standard dimension — no waiting for custom manufacturing. Ideal for \u003cstrong\u003ecommon window sizes found across UK housing stock\u003c\/strong\u003e, this unit ships from our Bristol warehouse with typical dispatch within 1–2 working days.\u003c\/p\u003e\u003cp\u003eBuilt from two panes of quality float glass with a sealed, gas-filled cavity, this unit drops straight into standard window frames designed for the 1000 × 800mm aperture — one of the most common residential window sizes in the UK.\u003c\/p\u003e\u003ch2\u003eSpecification\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 1000mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeight:\u003c\/strong\u003e 800mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfiguration:\u003c\/strong\u003e Standard double-glazed sealed unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall thickness:\u003c\/strong\u003e 24mm or 28mm (specify when ordering)\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThis fixed-size unit is ideal for glaziers who need a \u003cstrong\u003equick turnaround\u003c\/strong\u003e on common replacements. Keep stock of popular sizes to offer same-day service to your customers. Volume discounts available for trade accounts.\u003c\/p\u003e\u003cp\u003eManufactured to \u003cstrong\u003eBS EN 1279\u003c\/strong\u003e standards with our full \u003cstrong\u003e10-year manufacturer's warranty\u003c\/strong\u003e. Delivered nationwide with protective edge guards and transit packaging.\u003c\/p\u003e\u003cp\u003eFor non-standard sizes, use our \u003cstrong\u003eglass configurator\u003c\/strong\u003e to get instant pricing on custom-cut sealed units — manufactured to order at our Bristol facility.\u003c\/p\u003e","brand":"Pane Relief","offers":[{"title":"Compact","offer_id":60899495608650,"sku":"TG-COMPACT-MTM","price":200.0,"currency_code":"GBP","in_stock":true},{"title":"Standard","offer_id":60899495641418,"sku":"TG-STANDARD-MTM","price":500.0,"currency_code":"GBP","in_stock":true},{"title":"Large","offer_id":60899495674186,"sku":"TG-LARGE-MTM","price":1200.0,"currency_code":"GBP","in_stock":true},{"title":"Extra Large","offer_id":60899495706954,"sku":"TG-XL-MTM","price":2500.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_96471dcc-30fb-47d4-90f5-97802e8d8dac.webp?v=1773249496"},{"product_id":"safety-security-double-glazed-unit-made-to-measure","title":"Safety \u0026 Security Double-Glazed Unit – Made to Measure","description":"\u003ch2\u003eSafety \u0026amp; Security Double-Glazed Unit — Laminated, Attack-Resistant\u003c\/h2\u003e\u003cp\u003eWhen standard glass isn't enough, our \u003cstrong\u003eSafety \u0026amp; Security Double-Glazed Unit\u003c\/strong\u003e delivers certified attack resistance to \u003cstrong\u003eBS EN 356\u003c\/strong\u003e. Built with \u003cstrong\u003elaminated glass\u003c\/strong\u003e featuring PVB interlayers, this unit resists forced entry, impact, and accidental breakage — making it the right choice for ground-floor windows, doors, shopfronts, schools, and any application where security is paramount.\u003c\/p\u003e\u003cp\u003eUnlike toughened glass that shatters into small pieces on impact, laminated glass holds together when broken. The PVB interlayer bonds the glass fragments, maintaining a barrier even after multiple blows. This buys critical time during a break-in attempt and prevents dangerous glass shards from scattering.\u003c\/p\u003e\u003ch2\u003eAttack Resistance Classes\u003c\/h2\u003e\u003cp\u003eWe manufacture to all standard \u003cstrong\u003eBS EN 356\u003c\/strong\u003e resistance classes:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eP1A:\u003c\/strong\u003e Resists 3 impacts from a 4.11kg steel ball dropped from 1.5m — basic safety glass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP2A:\u003c\/strong\u003e 3 impacts from 3m drop height — enhanced safety\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP4A:\u003c\/strong\u003e 3 impacts from 9m drop height — anti-burglar rated\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP5A:\u003c\/strong\u003e 9 impacts from 9m drop height — high security\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eAll units also comply with \u003cstrong\u003eBS EN 12600\u003c\/strong\u003e impact safety classification, making them suitable for critical locations defined in Building Regulations Approved Document K (doors, side panels, low-level glazing below 800mm).\u003c\/p\u003e\u003cp\u003eMade to measure at our Bristol facility. Every unit carries \u003cstrong\u003eBS EN 1279\u003c\/strong\u003e certification and our \u003cstrong\u003e10-year warranty\u003c\/strong\u003e. \u003cstrong\u003eFENSA registered\u003c\/strong\u003e for Building Control compliance.\u003c\/p\u003e\u003cp\u003eConfigure your exact size, glass build-up, and security rating using our \u003cstrong\u003eglass configurator\u003c\/strong\u003e for instant pricing.\u003c\/p\u003e","brand":"Pane Relief","offers":[{"title":"Compact","offer_id":60899496558922,"sku":"TG-COMPACT-MTM","price":200.0,"currency_code":"GBP","in_stock":true},{"title":"Standard","offer_id":60899496591690,"sku":"TG-STANDARD-MTM","price":500.0,"currency_code":"GBP","in_stock":true},{"title":"Large","offer_id":60899496624458,"sku":"TG-LARGE-MTM","price":1200.0,"currency_code":"GBP","in_stock":true},{"title":"Extra Large","offer_id":60899496657226,"sku":"TG-XL-MTM","price":2500.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_96471dcc-30fb-47d4-90f5-97802e8d8dac.webp?v=1773249496"},{"product_id":"acoustic-triple-glazed-unit-44db-noise-reduction-16","title":"Acoustic Triple Glazed Unit - 44dB Noise Reduction (Residential Replacement)","description":"\u003ch2\u003eAcoustic Triple Glazed Unit — Residential Noise Reduction\u003c\/h2\u003e\u003cp\u003eLiving near a busy road, railway, or flight path? Our \u003cstrong\u003eAcoustic Triple Glazed Unit\u003c\/strong\u003e cuts external noise by \u003cstrong\u003e44dB\u003c\/strong\u003e — reducing thundering traffic to a gentle background murmur. Designed specifically for \u003cstrong\u003eresidential bedrooms, living rooms, and home offices\u003c\/strong\u003e where noise disrupts sleep, concentration, and quality of life.\u003c\/p\u003e\u003cp\u003eThe difference between standard double glazing (~28dB reduction) and this 44dB acoustic unit is dramatic. Sound reduction is measured logarithmically — every 10dB reduction halves the perceived noise level. At 44dB, you're cutting perceived noise to roughly one-quarter of what you hear through standard windows.\u003c\/p\u003e\u003ch2\u003eHow 44dB Acoustic Glazing Works\u003c\/h2\u003e\u003cp\u003eStandard sealed units use identical glass thicknesses on all panes — which creates resonance at specific frequencies, allowing noise through. Our acoustic units use \u003cstrong\u003easymmetric glass configurations\u003c\/strong\u003e (typically 6mm outer, 4mm middle, 6.4mm acoustic laminated inner) that break up resonance patterns across the full frequency spectrum.\u003c\/p\u003e\u003cp\u003eThe \u003cstrong\u003eacoustic PVB interlayer\u003c\/strong\u003e in the laminated pane is specifically formulated to dampen sound vibration — it's softer and more viscoelastic than standard PVB, absorbing energy rather than transmitting it. 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Manufactured to \u003cstrong\u003eBS EN 1279\u003c\/strong\u003e at our Bristol facility. \u003cstrong\u003eFENSA registered\u003c\/strong\u003e, \u003cstrong\u003e10-year warranty\u003c\/strong\u003e, nationwide delivery.\u003c\/p\u003e\u003cp\u003eUse our \u003cstrong\u003eglass configurator\u003c\/strong\u003e for instant custom pricing on your exact dimensions.\u003c\/p\u003e","brand":"Pane Relief","offers":[{"title":"Compact","offer_id":60899520840010,"sku":"TG-COMPACT-MTM","price":200.0,"currency_code":"GBP","in_stock":true},{"title":"Standard","offer_id":60899520872778,"sku":"TG-STANDARD-MTM","price":500.0,"currency_code":"GBP","in_stock":true},{"title":"Large","offer_id":60899520905546,"sku":"TG-LARGE-MTM","price":1200.0,"currency_code":"GBP","in_stock":true},{"title":"Extra Large","offer_id":60899520938314,"sku":"TG-XL-MTM","price":2500.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway.webp?v=1773313157"},{"product_id":"36mm-triple-glazed-unit-maximum-performance-9","title":"36mm Triple Glazed Unit - Maximum Performance (Residential Replacement)","description":"\u003ch2\u003e36mm Triple Glazed Unit — Maximum Home Performance\u003c\/h2\u003e\u003cp\u003eFor homeowners who want \u003cstrong\u003ethe very best thermal and acoustic insulation available\u003c\/strong\u003e, our 36mm Triple Glazed Unit delivers a centre-pane U-value of \u003cstrong\u003e0.6 W\/m²K\u003c\/strong\u003e — approaching Passive House territory without the premium price tag. This is our highest-performing standard triple unit, engineered for clients who refuse to compromise on comfort.\u003c\/p\u003e\u003cp\u003eThe difference is tangible. Rooms stay warmer with less heating input. Cold spots near windows disappear. Traffic noise drops to a whisper. If you have ever sat next to a window and felt the chill radiating from the glass, this unit eliminates that entirely.\u003c\/p\u003e\u003ch2\u003ePeak Thermal \u0026amp; Acoustic Performance\u003c\/h2\u003e\u003cp\u003eThe 36mm build-up uses \u003cstrong\u003e4mm-12mm-4mm-12mm-4mm\u003c\/strong\u003e configuration with \u003cstrong\u003edouble soft-coat Low-E coatings\u003c\/strong\u003e and the option of \u003cstrong\u003ekrypton or argon gas fill\u003c\/strong\u003e. The 12mm cavities are at the optimal width for gas-fill thermal performance, delivering the lowest U-value achievable in a standard triple-glazed format.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eU-value:\u003c\/strong\u003e 0.6 W\/m²K (centre pane)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight transmittance:\u003c\/strong\u003e ~62%\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSolar factor (g-value):\u003c\/strong\u003e 0.38\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSound reduction:\u003c\/strong\u003e ~38dB Rw\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall thickness:\u003c\/strong\u003e 36mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eManufactured to \u003cstrong\u003eBS EN 1279\u003c\/strong\u003e at our Bristol production facility. \u003cstrong\u003eFENSA registered\u003c\/strong\u003e, \u003cstrong\u003e10-year warranty\u003c\/strong\u003e, nationwide delivery with full transit protection.\u003c\/p\u003e\u003cp\u003eSpecify your exact dimensions and gas fill preference in our \u003cstrong\u003eglass configurator\u003c\/strong\u003e for instant pricing.\u003c\/p\u003e","brand":"Pane Relief","offers":[{"title":"Compact","offer_id":60899521331530,"sku":"TG-COMPACT-MTM","price":200.0,"currency_code":"GBP","in_stock":true},{"title":"Standard","offer_id":60899521364298,"sku":"TG-STANDARD-MTM","price":500.0,"currency_code":"GBP","in_stock":true},{"title":"Large","offer_id":60899521397066,"sku":"TG-LARGE-MTM","price":1200.0,"currency_code":"GBP","in_stock":true},{"title":"Extra Large","offer_id":60899521429834,"sku":"TG-XL-MTM","price":2500.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway.webp?v=1773313157"},{"product_id":"24mm-clear-double-glazed-unit","title":"24mm Clear Double Glazed Unit (Standard Argon)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe default replacement sealed unit for UK homes\u003c\/strong\u003e. A 24mm clear double-glazed unit (4mm clear \/ 16mm argon-filled cavity \/ 4mm clear) is the workhorse of British replacement glazing — fitted to the majority of post-2002 PVCu, aluminium, and timber frames, and the unit most failed (misted, blown, condensation-streaked) units in pre-2015 stock are being replaced with.\u003c\/p\u003e\n\n\u003cp\u003eThis flagship is built on Pilkington-grade 4mm float glass, a 16mm warm-edge spacer, and a 90% argon fill (factory-tested at 92-95% on initial fill, with 1% per annum loss assumed under BS EN 1279-2). Krypton fill is available as a custom-configure option for slim-cavity variants — for 24mm symmetric units, argon delivers the better cost-per-watt envelope.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e24mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear float \/ 16mm cavity \/ 4mm clear float\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3 compliant)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite (Edgetech Super Spacer or equivalent)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.4 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value (solar transmittance)\u003c\/th\u003e\n\u003ctd\u003e0.72\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance (LT)\u003c\/th\u003e\n\u003ctd\u003e~80%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279 (parts 1, 2, 3, 5, 6)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eManufactured\u003c\/th\u003e\n\u003ctd\u003eUK, FENSA-registered supply chain\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLike-for-like replacement\u003c\/strong\u003e of a failed (misted\/blown) post-2002 unit where the frame is sound and the existing rebate accepts a 24mm unit.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInternal partitions, porches, and unheated outbuildings\u003c\/strong\u003e where U-value isn't critical and 80% light transmittance matters.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eListed-building consents that permit DG\u003c\/strong\u003e where the unit must read as a clear single-pane sightline (24mm clear hides cavity from most viewing angles better than tinted\/coated alternatives).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBay windows, dormer cheeks, and small-aperture casements\u003c\/strong\u003e where the 600 × 400 stock size lands without trimming.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor applications where U-value is the priority (Building Regs Approved Document L compliance, new-build, A-rated specification), the \u003ca href=\"\/products\/28mm-low-e-a-rated-double-glazed-unit\"\u003e\u003cstrong\u003e28mm Low-E A-Rated\u003c\/strong\u003e\u003c\/a\u003e variant is the recommended upgrade — same form factor, U-value 1.1 W\/m²K, planitherm soft-coat.\u003c\/p\u003e\n\n\u003cp\u003eFor acoustic applications (railway lines, flight paths, A-roads), the \u003ca href=\"\/pages\/acoustic-glass\"\u003e\u003cstrong\u003eacoustic glass topical page\u003c\/strong\u003e\u003c\/a\u003e walks the Rw \/ dB-reduction math and links to the laminated alternatives.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are listed below. Each is dispatched 5-7 working days from order via our FENSA-registered manufacturing partners. Custom sizes — including shaped, tinted, low-E, toughened, and acoustic variants — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e with the same per-m² rate as the stock units (no custom-size premium).\u003c\/p\u003e\n\n\u003cp\u003eTrade accounts: log in to your account to see your tiered pricing — volume discount applies at 5+ units per order.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with a CE\/UKCA mark referencing BS EN 1279, a unique IGU stamp inside the cavity (visible at edge), and a Declaration of Performance available on request. Argon fill is tested per BS EN 1279-3 (initial fill ≥85%, annual loss \u0026lt;1% under EN-1279-2 accelerated weathering).\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWill this fit my existing frame?\u003c\/h3\u003e\n\u003cp\u003eCheck the rebate depth (the slot the glass sits in). A 24mm unit needs a rebate depth of at least 24mm + 3mm clearance = 27mm. Most post-2002 PVCu and aluminium frames accept this. Pre-2000 timber casements often had 20mm rebates designed for single glazing — those may need re-rebating or stepping to a slim 14mm Krypton unit.\u003c\/p\u003e\n\n\u003ch3\u003eHow long does a sealed unit last?\u003c\/h3\u003e\n\u003cp\u003eUK industry average is 15-25 years before edge-seal failure causes misting. Our units carry a 10-year manufacturer's warranty on seal integrity (BS EN 1279-2 accelerated-weathering tested). Argon retention is warranted to 80% of initial fill at 10 years.\u003c\/p\u003e\n\n\u003ch3\u003eArgon vs no-gas: does it matter?\u003c\/h3\u003e\n\u003cp\u003eYes. A 24mm air-filled unit has a centre-pane U-value of ~1.8 W\/m²K. The argon fill drops that to 1.4 — about a 22% improvement in winter heat retention. The £\/W improvement of argon is one of the best in residential glazing.\u003c\/p\u003e\n\n\u003ch3\u003eCan I get this with a low-E coating?\u003c\/h3\u003e\n\u003cp\u003eYes — use the configurator to add a Pilkington K or Optitherm soft-coat. The price uplift is computed live. Alternatively, the dedicated \u003ca href=\"\/products\/28mm-low-e-a-rated-double-glazed-unit\"\u003e28mm Low-E A-Rated flagship\u003c\/a\u003e is a single-button purchase.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the lead time for shaped or custom sizes?\u003c\/h3\u003e\n\u003cp\u003eStock sizes: 5-7 working days. Custom rectangular (non-stock): 7-10 working days. Shaped (arched, raked, circular): 10-14 working days. Tempered\/toughened: add 3 working days. All times exclude national-holiday weeks.\u003c\/p\u003e\n\n\u003ch3\u003eDo you fit, or supply only?\u003c\/h3\u003e\n\u003cp\u003eWe supply only — but we can recommend FENSA-registered fitters in your postcode area. Contact the helpline (08:00-18:00 Mon-Fri) for fitter introductions. Supply + fit packages route via partner installers; \u003ca href=\"\/pages\/contact-us\"\u003econtact us\u003c\/a\u003e for a quote.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61851582431562,"sku":"DG24-CLR-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61851582464330,"sku":"DG24-CLR-800x600","price":47.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61851582497098,"sku":"DG24-CLR-1000x800","price":79.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61851582529866,"sku":"DG24-CLR-1200x1000","price":118.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61851582562634,"sku":"DG24-CLR-1500x1200","price":176.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_54370c02-2440-4a9f-8880-a7b3c20db6b3.webp?v=1778952471"},{"product_id":"28mm-low-e-a-rated-double-glazed-unit","title":"28mm Low-E A-Rated Double Glazed Unit","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe A-rated upgrade\u003c\/strong\u003e. A 28mm low-E argon-filled sealed unit (4mm clear \/ 20mm cavity with planitherm soft-coat \/ 4mm clear) delivers a centre-pane U-value of 1.1 W\/m²K and a Window Energy Rating of A under BFRC certification — the spec UK building inspectors expect for Approved Document L compliance on replacement glazing.\u003c\/p\u003e\n\n\u003cp\u003e\"Low-E\" means low-emissivity: a microscopically-thin metallic-oxide coating on the inside face of the inner pane that reflects long-wave heat radiation back into the room while letting visible light through. The Pilkington K-Glass (hard-coat) and Optitherm S1 \/ Planitherm Total+ (soft-coat) families are the UK-standard options — soft-coat performs better thermally but must be sealed inside the cavity (it oxidises if exposed to air, which is why it always faces the cavity, never the room).\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 20mm argon cavity \/ 4mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black (low thermal bridging)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.1 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window with PVCu frame)\u003c\/th\u003e\n\u003ctd\u003e1.4 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.62\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~78%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA (when fitted in a compliant frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673 (U-value), BS EN 410 (light\/solar)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is required\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBuilding Regs Approved Document L\u003c\/strong\u003e — Part L1B requires replacement window units to meet a U-value of 1.4 W\/m²K or better. A 28mm Low-E argon unit clears that with 0.3 W\/m²K of headroom.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNew build and significant extensions\u003c\/strong\u003e — Local building control will check that replacement glazing in extensions ≥ 30% of floor area meets Part L. This unit is the default A-rated spec.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCold-room retrofits\u003c\/strong\u003e — North-facing bedrooms, single-glazed conservatories being upgraded, rooms above unheated garages. The 1.1 U-value cuts radiant heat loss roughly 22% vs a standard 24mm argon unit.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEPC band improvement\u003c\/strong\u003e — Upgrading to A-rated glazing typically lifts an EPC by 5-10 points depending on the existing baseline. For landlords, this is a route to MEES C compliance ahead of the 2028 deadline.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eEnergy-rated glass selection in depth is covered on the \u003ca href=\"\/pages\/energy-rated-glass-units\"\u003e\u003cstrong\u003eenergy-rated glass topical page\u003c\/strong\u003e\u003c\/a\u003e — U-value vs g-value tradeoffs, BFRC vs CE-label differences, and how the WER calculation actually works.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are below. Each is dispatched 5-7 working days from a FENSA-registered manufacturing partner. Custom sizes via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e at the same per-m² rate. Trade accounts see tiered pricing on login.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with a UKCA mark, a unique IGU edge-stamp identifying the manufacturer batch, and a Declaration of Performance referencing BS EN 1279 (parts 1, 2, 3, 5, 6). The Planitherm coating carries Saint-Gobain's batch certification. BFRC ratings are issued on the whole-window assembly (frame + glass); the glass alone contributes the U=1.1 centre-pane figure, with the frame contributing the rest.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWhat's the difference between A-rated, B-rated, and C-rated glass?\u003c\/h3\u003e\n\u003cp\u003eThe BFRC Window Energy Rating combines U-value (heat loss), g-value (solar gain), and L-factor (air leakage). A-rated requires WER ≥ 0 — meaning solar gain offsets heat loss over a year. C-rated allows WER -20. A 28mm Low-E argon unit in a standard PVCu frame is the simplest path to an A rating.\u003c\/p\u003e\n\n\u003ch3\u003eSoft-coat vs hard-coat low-E?\u003c\/h3\u003e\n\u003cp\u003eHard-coat (Pilkington K) is pyrolytic — fused into the glass at the float-line, durable, can be toughened, slightly worse U-value (~1.5 W\/m²K in a 28mm unit). Soft-coat (Planitherm\/Optitherm) is sputter-deposited, higher performance (1.1 W\/m²K), must live inside the sealed cavity. This flagship uses Planitherm Total+ on face 3.\u003c\/p\u003e\n\n\u003ch3\u003eWill fitting A-rated glass alone improve my EPC?\u003c\/h3\u003e\n\u003cp\u003eYes — replacement glazing scores under \"windows\" in the EPC RdSAP model. The improvement depends on the previous baseline: replacing single-glazed sash windows with A-rated DG can add 8-12 EPC points; replacing first-generation DG (1990s) typically adds 3-5 points.\u003c\/p\u003e\n\n\u003ch3\u003eCan I use this in a listed building?\u003c\/h3\u003e\n\u003cp\u003eListed-building consent is local-authority-dependent. Conservation officers usually accept slim or low-iron variants where sightline matters. The 28mm Low-E is too thick for most original Georgian sash rebates — for those, consider the \u003ca href=\"\/pages\/slim-double-glazing\"\u003eslim Krypton variant\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eDoes the Planitherm coating tint the glass?\u003c\/h3\u003e\n\u003cp\u003eSlightly. There's a faint neutral\/bronze haze visible at sharp viewing angles, particularly with the sun behind you. From inside looking out, the tint is invisible. Light transmittance drops from ~80% (uncoated) to ~78% — imperceptible in normal use.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10-year manufacturer warranty on edge-seal integrity (BS EN 1279-2 weathering) and 5-year warranty on coating integrity (Planitherm batch certification). Argon retention warranted to 80% of initial fill at 10 years.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61851582660938,"sku":"DG28-LOWE-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61851582693706,"sku":"DG28-LOWE-800x600","price":59.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61851582726474,"sku":"DG28-LOWE-1000x800","price":98.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61851582759242,"sku":"DG28-LOWE-1200x1000","price":147.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61851582792010,"sku":"DG28-LOWE-1500x1200","price":220.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_fc56842d-dbfd-4b3b-8927-69d95e679010.webp?v=1778952473"},{"product_id":"36mm-standard-triple-glazed-unit","title":"36mm Standard Triple Glazed Unit (Argon)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eTwo sealed cavities, three panes, U-value 0.8 W\/m²K\u003c\/strong\u003e. A 36mm triple-glazed unit (4mm \/ 12mm argon \/ 4mm \/ 12mm argon \/ 4mm) is the Scandinavian default — the spec that goes into Norwegian, Finnish, and German new-build as the entry-level energy spec. In the UK, it's the upgrade path from A-rated double when winter heat loss matters more than installed cost.\u003c\/p\u003e\n\n\u003cp\u003eTriple glazing's value isn't just lower U — it's a warmer inner-pane surface temperature. With external air at -2°C and interior at 21°C, a double-glazed unit's interior pane sits around 11°C (touch-cold). A triple-glazed unit's interior pane sits around 17°C — close enough to room temperature that radiant chill against the body, and condensation on cold glass, both effectively disappear.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e36mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 12mm argon \/ 4mm clear \/ 12mm argon \/ 4mm clear\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCavities\u003c\/th\u003e\n\u003ctd\u003e2 × 12mm argon-filled (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bars\u003c\/th\u003e\n\u003ctd\u003e2 × warm-edge composite\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e0.8 W\/m²K (with low-E on inner face)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (uncoated)\u003c\/th\u003e\n\u003ctd\u003e1.0 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.55\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~71%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~30 kg\/m² (vs ~20 kg\/m² for 24mm DG — confirm frame load capacity)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, Passivhaus-compatible per PHI thermal requirements\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere triple glazing is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCold-climate orientation\u003c\/strong\u003e — north-facing bedrooms, exposed elevations, top-floor rooms under uninsulated lofts.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePassivhaus and EnerPHit retrofits\u003c\/strong\u003e — Passivhaus Institut requires whole-window U ≤ 0.8 W\/m²K. A 36mm triple unit in a thermally-broken aluminium or timber frame is the standard route.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAcoustic-plus-thermal stacks\u003c\/strong\u003e — combine triple panes with asymmetric thicknesses (4-12-6-12-4 or laminated outer) for Rw 38-44 dB while maintaining 0.8 U-value. See the \u003ca href=\"\/products\/acoustic-triple-glazed-unit-44db-noise-reduction-16\"\u003eacoustic triple variant\u003c\/a\u003e for the 44dB spec.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHeat-pump and MVHR retrofits\u003c\/strong\u003e — air-source heat pumps work most efficiently at low flow temperatures (35-45°C). Triple glazing's lower fabric heat loss lets the heat pump hold setpoint without bumping flow temp.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full thermal-vs-cost analysis is on the \u003ca href=\"\/pages\/triple-glazing\"\u003e\u003cstrong\u003etriple glazing topical page\u003c\/strong\u003e\u003c\/a\u003e — including the payback-period math, frame-load implications, and when triple genuinely outperforms A-rated double.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below. Dispatch 5-7 working days. Custom sizes including shaped, oversized (\u0026gt;1500mm any dimension), and laminated variants are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e. Trade accounts see tiered pricing.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrame load note:\u003c\/strong\u003e triple-glazed units are ~50% heavier than double-glazed equivalents. Confirm hinge capacity, sash weight rating, and reinforcement spec on your frames before ordering. Most modern PVCu profiles are rated for triple — older or budget profiles may need steel reinforcement.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA-marked, BS EN 1279 compliant across all six parts. PHI-certified manufacturers carry an additional Passivhaus-component certification — request this stamp at order if specifying for a Passivhaus project.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eIs triple glazing worth the cost in the UK?\u003c\/h3\u003e\n\u003cp\u003eFor new-build and major retrofit: yes, especially with heat pumps where lower fabric loss directly improves COP. For straight replacement on a Victorian terrace: the payback period is long (15-25 years) and A-rated double often delivers 80% of the benefit at 60% of the cost. Use the configurator's energy-saving estimator for your specific situation.\u003c\/p\u003e\n\n\u003ch3\u003eWill my existing frame take a 36mm unit?\u003c\/h3\u003e\n\u003cp\u003eMost modern PVCu and aluminium frames are designed for 28mm units. Some 70mm-depth systems accept 36mm with no modification; others need a deeper bead or full reglaze-bead replacement. Send a frame profile photo via \u003ca href=\"\/pages\/contact-us\"\u003eour contact form\u003c\/a\u003e for a compatibility check.\u003c\/p\u003e\n\n\u003ch3\u003eWhy is g-value lower than double glazing?\u003c\/h3\u003e\n\u003cp\u003eEach pane reflects and absorbs some solar radiation. Three panes reflect\/absorb more than two. The triple-glazed g-value of ~0.55 vs the A-rated double's ~0.62 means slightly less passive solar heat gain in winter — for south-facing principal rooms in a UK climate, this is genuinely a small downside.\u003c\/p\u003e\n\n\u003ch3\u003eArgon vs krypton vs xenon?\u003c\/h3\u003e\n\u003cp\u003eFor 12mm cavities (this unit), argon is optimal — krypton's benefit appears only in cavities ≤ 8mm. For slim-cavity triple (10-10mm), krypton is worth the premium. Xenon is rarely cost-justified outside specialist Passivhaus components.\u003c\/p\u003e\n\n\u003ch3\u003eNoise reduction vs double?\u003c\/h3\u003e\n\u003cp\u003eMarginal — Rw of ~33 dB vs A-rated double's ~31 dB. If acoustic is the priority, asymmetric pane thicknesses or laminated panes deliver much more than adding a third pane. See the dedicated acoustic flagships.\u003c\/p\u003e\n\n\u003ch3\u003eCondensation on the outside?\u003c\/h3\u003e\n\u003cp\u003eYes, occasionally — and counterintuitively, it's a sign the glass is performing well. With triple glazing, the outer-pane surface stays close to outdoor dew point on clear cold nights (because almost no heat is leaking out to warm it). Outside-face dew is a feature, not a defect.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61851583054154,"sku":"TG36-STD-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61851583086922,"sku":"TG36-STD-800x600","price":71.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61851583119690,"sku":"TG36-STD-1000x800","price":118.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61851583152458,"sku":"TG36-STD-1200x1000","price":176.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61851583185226,"sku":"TG36-STD-1500x1200","price":264.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_758c92a7-342a-41e9-9e33-653ba1e180ac.webp?v=1778952476"},{"product_id":"28mm-safety-toughened-double-glazed-unit","title":"28mm Safety Toughened Double Glazed Unit (BS EN 12150)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eSafety glass where it's legally required\u003c\/strong\u003e. A 28mm sealed unit with both panes toughened to BS EN 12150 (Class 1(C)1 impact rating) is the unit Approved Document N of the Building Regulations mandates in \"critical locations\" — areas where human impact on glass is a foreseeable risk.\u003c\/p\u003e\n\n\u003cp\u003e\"Critical location\" is defined in Approved Document N as: glazing at low level (≤ 800mm above floor in walls, ≤ 1500mm in doors), glazing within 300mm of a door edge, glazing in bathrooms or shower enclosures, and glazing in any other location where a person could foreseeably impact the pane. In domestic settings, this typically means: French doors, sidelights, low-level windows in living rooms, conservatory side-panels, and bathroom\/en-suite windows.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm toughened \/ 20mm argon cavity \/ 4mm toughened\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eToughening standard\u003c\/th\u003e\n\u003ctd\u003eBS EN 12150-1 (heat treatment) + BS EN 12600 (impact)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eImpact classification\u003c\/th\u003e\n\u003ctd\u003eClass 1(C)1 (pendulum drop, fall height 1200mm, no penetration)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBreak pattern\u003c\/th\u003e\n\u003ctd\u003eGranular (small blunt cubes, low laceration risk)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane, uncoated)\u003c\/th\u003e\n\u003ctd\u003e1.4 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (with low-E upgrade)\u003c\/th\u003e\n\u003ctd\u003e1.1 W\/m²K — configurable\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~80%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 12150, BS EN 12600, BS 6206 (legacy reference)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere the law requires this unit\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFrench doors and patio doors\u003c\/strong\u003e — full-height glazing in entrance\/garden doors must be Class 1(C)1 or laminated equivalent.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDoor sidelights within 300mm of the door edge, up to 1500mm above floor level\u003c\/strong\u003e — Approved Document N, diagram 1.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLow-level windows ≤ 800mm above floor\u003c\/strong\u003e — common in 1990s+ open-plan living rooms with full-height fenestration.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBathroom, en-suite, and wet-room glazing\u003c\/strong\u003e — any location where wet-floor slips toward a window are foreseeable.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShower enclosures and bath screens\u003c\/strong\u003e — although usually monolithic toughened, sealed-unit specifications occasionally appear in external bathroom windows.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservatory side panels and roof bars\u003c\/strong\u003e — overhead glazing (roof) usually requires laminated, not toughened, for fragmentation safety; side panels typically require toughened.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full safety-glazing decision tree (toughened vs laminated vs heat-strengthened) is on the \u003ca href=\"\/pages\/safety-security-glass\"\u003e\u003cstrong\u003esafety \u0026amp; security glass topical page\u003c\/strong\u003e\u003c\/a\u003e — including the laminated alternative for overhead applications, and the anti-bandit P-rated upgrade path.\u003c\/p\u003e\n\n\u003ch2\u003eToughened vs laminated — which to specify\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eToughened\u003c\/strong\u003e (this flagship): heat-treated glass, breaks into small granular cubes. Strong, impact-resistant, low laceration risk. Cannot be cut or drilled after toughening. Risk: spontaneous breakage from nickel-sulphide inclusion (rare — ~1 in 8 tonnes; mitigable via heat-soak testing for high-risk applications).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eLaminated\u003c\/strong\u003e: two glass plies with PVB interlayer. On impact, breaks but the interlayer holds the fragments in place. Mandated for overhead glazing (BS 5516), security applications, and where fall-from-height is a risk. Higher cost, slightly lower light transmittance.\u003c\/p\u003e\n\n\u003cp\u003eFor most residential critical locations, toughened is the cost-optimal correct spec. For roof glazing, balconies, balustrades, and security-priority entrances, laminated or heat-soaked-toughened is the right call. The configurator surfaces both options with live pricing.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below. Dispatch 5-7 working days (toughening adds ~3 working days vs the standard clear unit). Custom sizes via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e. Trade accounts see tiered pricing.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit carries a permanent BS EN 12150 \/ Kitemark stamp etched in one corner — usually 30mm from the edge, visible in the rebate after fitting. Heat-soak testing (BS EN 14179) is available as an order option for high-risk applications (overhead, large-span, balustrade-adjacent) where spontaneous breakage risk warrants the additional process step.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow do I know if my window is a \"critical location\"?\u003c\/h3\u003e\n\u003cp\u003eMeasure the lowest edge of the pane above the floor. If ≤ 800mm in a wall or ≤ 1500mm in a door (or within 300mm of a door edge), it's critical and needs safety glass. Building Control inspectors will check this on any building-regs-notifiable replacement. \u003ca href=\"\/pages\/safety-security-glass\"\u003eThe topical page\u003c\/a\u003e walks the full Approved Document N decision tree.\u003c\/p\u003e\n\n\u003ch3\u003eCan I tell toughened from regular glass after fitting?\u003c\/h3\u003e\n\u003cp\u003eYes — every toughened pane carries a permanent etched stamp (\"TOUGHENED \/ BS EN 12150 \/ [manufacturer]\") in one corner, usually visible 20-30mm in from the edge inside the rebate or at the corner. Hold a phone torch at a low angle to find it. No stamp = not toughened.\u003c\/p\u003e\n\n\u003ch3\u003eWhy does toughened cost more?\u003c\/h3\u003e\n\u003cp\u003eProcess: regular float glass is cut to size, edge-polished, then heated to ~620°C and rapidly cooled. The differential cooling creates surface compression and central tension — this is what makes it 4-5× stronger than annealed glass. Once toughened, it cannot be cut, drilled, or notched. So all sizing must be exact at the toughening stage, with zero scrap recovery. Premium is typically 15-25%.\u003c\/p\u003e\n\n\u003ch3\u003eCan toughened be combined with low-E?\u003c\/h3\u003e\n\u003cp\u003eYes — but the low-E coating must be hard-coat (Pilkington K) because soft-coat planitherm doesn't survive the 620°C toughening temperature. Configure with \"hard-coat low-E\" for the A-rated + safety stack.\u003c\/p\u003e\n\n\u003ch3\u003eIs toughened secure against intruders?\u003c\/h3\u003e\n\u003cp\u003eNot the right tool. Toughened breaks in one impact event (granular shower) — once broken, there's no residual barrier. For security, specify laminated (BS EN 14449) or anti-bandit P-rated (BS EN 356) glass. The \u003ca href=\"\/pages\/safety-security-glass\"\u003esafety topical page\u003c\/a\u003e covers the security upgrade path.\u003c\/p\u003e\n\n\u003ch3\u003eSpontaneous breakage — should I worry?\u003c\/h3\u003e\n\u003cp\u003eFor most residential applications: no. Nickel-sulphide inclusions causing spontaneous breakage occur at roughly 1 per 8 tonnes of float feedstock. For large-span overhead glazing, balustrades, and high-value retail facades, specify heat-soak-tested (BS EN 14179) toughened — adds ~£8\/m² and reduces NiS risk by \u0026gt;99%.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61851583545674,"sku":"DG28-TGH-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61851583578442,"sku":"DG28-TGH-800x600","price":54.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61851583611210,"sku":"DG28-TGH-1000x800","price":90.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61851583643978,"sku":"DG28-TGH-1200x1000","price":135.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61851583676746,"sku":"DG28-TGH-1500x1200","price":203.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_3d8bad1a-08fe-466b-958b-b22c444b99f1.webp?v=1778952477"},{"product_id":"specialist-acoustic-laminated-glass-asymmetric-double-glazed-unit","title":"Specialist Acoustic Laminated Double Glazed Unit (8.8 + 4mm Asymmetric)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe cost-optimal acoustic flagship — Rw 40 dB in a 28mm double-glazed envelope\u003c\/strong\u003e. An asymmetric double-glazed unit with an 8.8mm acoustic-PVB laminated outer pane and a 4mm clear inner, separated by a 14mm argon-filled cavity, delivers acoustic performance previously only available from triple glazing — at roughly half the cost and weight.\u003c\/p\u003e\n\n\u003cp\u003eFor most urban-noise-mitigation projects, this is the right unit. It fits standard 28mm double-glazed rebates, weighs about 23 kg\/m² (not the 38 kg\/m² of acoustic triple), and achieves an Rw of 40 dB — a 10-12 dB improvement over a typical 1990s 4-12-4 double. The perceived loudness reduction is roughly halving — traffic that previously dominated a room moves into the background.\u003c\/p\u003e\n\n\u003ch2\u003eAsymmetric build — why it works\u003c\/h2\u003e\n\u003cp\u003eSymmetric double-glazed units (4-12-4, 4-20-4) have a coincidence-frequency dip where the two identical panes resonate together. Sound at that frequency punches through. Replacing one pane with a thicker laminated build shifts the coincidence frequency of that pane to a different band — so the two panes' dips no longer coincide.\u003c\/p\u003e\n\n\u003cp\u003eThe acoustic PVB interlayer in the 8.8mm laminate adds viscoelastic damping. Standard PVB (used in safety lamination) helps mildly. Acoustic-grade PVB (e.g., Trosifol SC, Saflex Q) is engineered with specific viscoelastic properties tuned to road and rail frequency bands — it absorbs 3-5 dB more than standard PVB across the critical 500-2500 Hz range.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e~28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e8.8mm acoustic-laminated outer (4+4 with 0.76mm acoustic PVB) \/ 14mm argon cavity \/ 4mm clear inner with optional low-E\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOuter-pane standard\u003c\/th\u003e\n\u003ctd\u003eBS EN 14449 (laminated)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eR\u003csub\u003ew\u003c\/sub\u003e (Weighted Sound Reduction Index)\u003c\/th\u003e\n\u003ctd\u003e40 dB to BS EN ISO 717-1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eR\u003csub\u003ew\u003c\/sub\u003e + C\u003csub\u003etr\u003c\/sub\u003e (road-traffic spectrum)\u003c\/th\u003e\n\u003ctd\u003e36-37 dB (typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane, with low-E inner face 3)\u003c\/th\u003e\n\u003ctd\u003e1.2 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (without low-E)\u003c\/th\u003e\n\u003ctd\u003e1.5 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.58\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~78%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~23 kg\/m² (manageable load in standard frames)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN ISO 717-1, BS EN 14449, BS EN 12600 (impact class 2(B)2 via laminated)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUrban frontage facing busy A-roads, ring roads, or town-centre traffic\u003c\/strong\u003e — typical existing R\u003csub\u003ew\u003c\/sub\u003e 28-30 dB, upgrading to 40 dB roughly halves perceived noise.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperties within 200m of a railway line\u003c\/strong\u003e — particularly Network Rail main lines, freight routes, and HS2\/Crossrail corridors. Asymmetric stacks handle low-frequency rail noise better than symmetric.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlight-path properties outside the 60 dB L\u003csub\u003eAeq,16h\u003c\/sub\u003e contour\u003c\/strong\u003e where R\u003csub\u003ew\u003c\/sub\u003e 40 typically delivers an acceptable internal noise level without needing the cost\/weight of acoustic triple.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApartment buildings and HMOs\u003c\/strong\u003e where Approved Document E (sound insulation between dwellings) compliance crosses with external glazing performance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBoutique hotels and serviced apartments\u003c\/strong\u003e where guest noise expectations drive specification.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHome offices and recording studios\u003c\/strong\u003e in urban areas where noise floors below ~35 dB are the target.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full acoustic-glass guide, including the R\u003csub\u003ew\u003c\/sub\u003e vs R\u003csub\u003ew\u003c\/sub\u003e+C\u003csub\u003etr\u003c\/sub\u003e distinction, frame-seal advice, and acoustic trickle-vent guidance, is on the \u003ca href=\"\/pages\/acoustic-glass\"\u003e\u003cstrong\u003eacoustic glass topical page\u003c\/strong\u003e\u003c\/a\u003e. For the highest-performance acoustic spec (44 dB Rw triple-glazed), see the \u003ca href=\"\/products\/triple-glazed-acoustic-unit-44db-rw\"\u003eTriple Glazed Acoustic flagship\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are below. Dispatch 10-14 working days (acoustic-PVB lamination adds ~5 days to standard DG manufacturing). Custom sizes — including shaped, oversized, and bespoke pane-asymmetry builds (e.g., 8.8 + 6.4 for max-mass at boundaries) — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with: UKCA mark, BS EN 1279 DoP, R\u003csub\u003ew\u003c\/sub\u003e test certificate from a UKAS-accredited acoustic lab (BS EN ISO 10140 methodology), BS EN 14449 laminated-glass certificate on the outer pane, and BS EN 12600 impact classification (Class 2(B)2 via the laminated outer — meets most Approved Document N critical-location requirements as a side benefit). For noise-mitigation grant applications, we supply the R\u003csub\u003ew\u003c\/sub\u003e + C\u003csub\u003etr\u003c\/sub\u003e + C figures as a complete documentation pack.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow much quieter, in practice?\u003c\/h3\u003e\n\u003cp\u003eA 10-12 dB improvement is perceived as roughly halving loudness. If the room currently registers 50 dB(A) of background noise from outside (a typical urban room with 1990s DG facing a busy road), this upgrade typically drops that to 38-40 dB(A) — closer to a quiet residential street. The improvement is most noticeable for speech-intelligibility-band frequencies; low-frequency rumble drops less.\u003c\/p\u003e\n\n\u003ch3\u003eDoes it block low-frequency noise (lorries, basses)?\u003c\/h3\u003e\n\u003cp\u003ePartially. Low frequencies (below 250 Hz) are hard to block with glass mass alone — they're better attenuated with secondary glazing or mass-loaded walls. This unit drops low-frequency noise about 6-8 dB, vs 12-15 dB at mid frequencies. For dominant low-frequency sources (heavy goods routes, freight rail), R\u003csub\u003ew\u003c\/sub\u003e+C\u003csub\u003etr\u003c\/sub\u003e is the more honest figure (36-37 dB vs 40 dB R\u003csub\u003ew\u003c\/sub\u003e).\u003c\/p\u003e\n\n\u003ch3\u003eCan I get this as a triple-glazed unit?\u003c\/h3\u003e\n\u003cp\u003eYes — the \u003ca href=\"\/products\/triple-glazed-acoustic-unit-44db-rw\"\u003eTriple Glazed Acoustic Unit (44 dB Rw)\u003c\/a\u003e adds a third pane for a further 4 dB improvement, at additional cost and weight. For most projects, the double-glazed asymmetric flagship is the cost-optimal sweet spot.\u003c\/p\u003e\n\n\u003ch3\u003eWill my existing frame take this?\u003c\/h3\u003e\n\u003cp\u003eAt 28mm overall, this fits the same rebates as a standard 28mm DG — modern PVCu, aluminium, and timber frames designed for double glazing. The 23 kg\/m² weight is typically inside hinge ratings for windows up to 1500×1200. Confirm sash-balance ratings for very large units.\u003c\/p\u003e\n\n\u003ch3\u003eAcoustic PVB vs standard PVB — is the upgrade worth it?\u003c\/h3\u003e\n\u003cp\u003eYes, for acoustic-priority projects. Acoustic-grade PVB adds 3-5 dB across the 500-2500 Hz speech-intelligibility band over standard PVB at roughly £10-15\/m² premium. For a £200 unit, that's a 5-8% price increase for a 10-15% perceived noise reduction — typically the best £\/dB in the configurator.\u003c\/p\u003e\n\n\u003ch3\u003eSide-benefit: does this also count as safety glass?\u003c\/h3\u003e\n\u003cp\u003eYes. The laminated outer pane satisfies BS EN 12600 Class 2(B)2 — adequate for most critical locations under Approved Document N (door sidelights, low-level windows, bathroom glazing). For Class 1(C)1 (highest impact rating), specify toughened-plus-laminated in the configurator.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on PVB delamination (BS EN 14449 standard). 10 years on argon retention to ≥80% of initial fill. R\u003csub\u003ew\u003c\/sub\u003e performance is warranted at the certified test value at installation date — frame-seal degradation over time is excluded from the glass warranty.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853203005770,"sku":"DG-AC40-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853203038538,"sku":"DG-AC40-800x600","price":61.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853203071306,"sku":"DG-AC40-1000x800","price":102.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853203104074,"sku":"DG-AC40-1200x1000","price":153.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853203136842,"sku":"DG-AC40-1500x1200","price":229.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_779ff7fb-4383-47d1-b092-538c3ce8986a.webp?v=1779007259"},{"product_id":"triple-glazed-acoustic-unit-44db-rw","title":"Triple Glazed Acoustic Unit (44 dB Rw)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe hard-spec acoustic flagship — 44 dB Rw under BS EN ISO 717-1\u003c\/strong\u003e. A triple-glazed unit built with asymmetric pane thicknesses, an acoustic-PVB laminated outer, and twin argon-filled cavities tuned to disrupt coincidence-frequency resonance. This is the unit specified by acoustic consultants for properties under flight paths, on A-road frontage, in rail-corridor housing, and against the M25.\u003c\/p\u003e\n\n\u003cp\u003eRw 44 dB is meaningful: the perceived loudness reduction from outside to inside is roughly four times — the difference between a busy A-road at 70 dB(A) sounding like background conversation, and the same road sounding like a quiet office. Combined with a frame and trickle-vent assembly compatible with acoustic performance (sealed perimeter, acoustic vents where required), this unit drives whole-window R\u003csub\u003ew\u003c\/sub\u003e performance into the 40-43 dB range — territory previously only reachable with secondary glazing.\u003c\/p\u003e\n\n\u003ch2\u003eWhy asymmetric panes — the physics\u003c\/h2\u003e\n\u003cp\u003eGlass blocks sound by mass: thicker panes block more. But every pane has a \"coincidence frequency\" — a frequency at which the acoustic wave matches a resonant flexural mode of the pane, and the pane suddenly stops blocking sound. For 4mm float, coincidence is around 3000 Hz; for 6mm it shifts to ~2000 Hz; for laminated 8.8mm it spreads across a wider band but with lower peak dip thanks to the PVB damping.\u003c\/p\u003e\n\n\u003cp\u003eAn asymmetric stack — 8.8mm acoustic-laminated outer \/ 4mm middle \/ 4mm inner — places coincidence dips at different frequencies in each pane, so a single frequency can't punch through the assembly. The acoustic PVB interlayer adds viscoelastic damping that further suppresses the laminated pane's dip. Together, these mechanisms drive R\u003csub\u003ew\u003c\/sub\u003e 5-7 dB above what a symmetric triple at the same total mass would deliver.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e~42-44mm (asymmetric build)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e8.8mm acoustic-PVB laminated outer (4+4 with 0.76mm acoustic interlayer) \/ 12mm argon \/ 4mm clear \/ 12mm argon \/ 4mm clear\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCavities\u003c\/th\u003e\n\u003ctd\u003e2 × 12mm argon-filled (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eR\u003csub\u003ew\u003c\/sub\u003e (Weighted Sound Reduction Index)\u003c\/th\u003e\n\u003ctd\u003e44 dB to BS EN ISO 717-1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eR\u003csub\u003ew\u003c\/sub\u003e + C\u003csub\u003etr\u003c\/sub\u003e (road traffic spectrum)\u003c\/th\u003e\n\u003ctd\u003e40-41 dB (typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane, with low-E)\u003c\/th\u003e\n\u003ctd\u003e0.8 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.52\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~70%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~38 kg\/m² — confirm frame load capacity\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN ISO 717-1 (acoustic), BS EN 14449 (laminated), BS EN 12600 (impact via laminated)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHeathrow, Gatwick, Manchester, Stansted, Birmingham flight-path frontage\u003c\/strong\u003e — particularly for properties inside the 57 dB L\u003csub\u003eAeq,16h\u003c\/sub\u003e noise contour where local-authority noise insulation grants may apply.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eA-road and motorway-adjacent housing\u003c\/strong\u003e — particularly retrofit projects where existing single or first-generation double glazing is delivering only R\u003csub\u003ew\u003c\/sub\u003e 25-28 dB.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRail-corridor properties\u003c\/strong\u003e — main-line Network Rail routes, HS1, HS2, Crossrail. Train noise has a strong low-frequency component that asymmetric stacks handle better than symmetric.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHotels, hospitals, schools, and residential care in urban centres\u003c\/strong\u003e — where building-regs Approved Document E (sound insulation) requires verified performance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRecording studios, home cinemas, and high-spec residential\u003c\/strong\u003e — where guaranteed noise floors drive acoustic specifications regardless of external noise.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full acoustic-glazing decision tree — laminated vs asymmetric vs triple, Rw vs Rw+Ctr, and how the dB(A) reduction translates to perceived loudness — is on the \u003ca href=\"\/pages\/acoustic-glass\"\u003e\u003cstrong\u003eacoustic glass topical page\u003c\/strong\u003e\u003c\/a\u003e, with installation and frame-seal advice. For a simpler double-glazed acoustic option, see the \u003ca href=\"\/products\/specialist-acoustic-laminated-glass-asymmetric-double-glazed-unit\"\u003eSpecialist Acoustic Laminated double-glazed flagship\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are below. Dispatch 14-18 working days (acoustic-PVB lamination + triple-glazed assembly is a longer process than standard triple). Custom sizes — including bespoke acoustic stacks tuned to a specific noise spectrum (e.g., low-frequency dominant rail noise) — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e with an option for a free acoustic-consultant phone consultation.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrame load note:\u003c\/strong\u003e at ~38 kg\/m² this is one of the heaviest mainstream IGUs available. A 1500 × 1200 unit is ~68 kg. Specify reinforced hinges and check sash-balance ratings. Aluminium and laminated-timber frames are the appropriate choices; older PVCu frames typically cannot accept this load.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with: UKCA mark, BS EN 1279 DoP, R\u003csub\u003ew\u003c\/sub\u003e test certificate from a UKAS-accredited acoustic laboratory (BS EN ISO 10140 test methodology), laminated-glass BS EN 14449 certification, and CWCT (Centre for Window \u0026amp; Cladding Technology) test pack on request. For local-authority noise-grant applications, we can supply the R\u003csub\u003ew\u003c\/sub\u003e + C\u003csub\u003etr\u003c\/sub\u003e + C figures as a pack.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWhat does R\u003csub\u003ew\u003c\/sub\u003e 44 dB actually sound like vs my current windows?\u003c\/h3\u003e\n\u003cp\u003eA typical 1990s 4-12-4 double-glazed unit achieves R\u003csub\u003ew\u003c\/sub\u003e 28-30 dB. Upgrading to R\u003csub\u003ew\u003c\/sub\u003e 44 dB is a 14-16 dB improvement — perceived as roughly a 75% loudness reduction. Heavy traffic that previously dominated the room drops to the level of background conversation. Note: this assumes a fully-sealed frame and acoustic-compatible trickle vents; air leakage paths around the unit can lose 8-10 dB.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the difference between R\u003csub\u003ew\u003c\/sub\u003e, R\u003csub\u003ew\u003c\/sub\u003e+C\u003csub\u003etr\u003c\/sub\u003e, and dB(A)?\u003c\/h3\u003e\n\u003cp\u003eR\u003csub\u003ew\u003c\/sub\u003e is a single-number weighted index across 100-3150 Hz (BS EN ISO 717-1). C\u003csub\u003etr\u003c\/sub\u003e is a correction factor weighted toward road-traffic frequencies (low-frequency-heavy). R\u003csub\u003ew\u003c\/sub\u003e+C\u003csub\u003etr\u003c\/sub\u003e is the more honest figure for road-noise scenarios. dB(A) is an A-weighted decibel level, used for measuring actual noise — not for rating glass.\u003c\/p\u003e\n\n\u003ch3\u003eIs triple acoustic actually better than the best double acoustic?\u003c\/h3\u003e\n\u003cp\u003eMarginally — typically 2-4 dB at the high end. The R\u003csub\u003ew\u003c\/sub\u003e improvement from double-to-triple is smaller than asymmetric-pane mass gains within a double. The case for triple acoustic is when you want both Rw 42+ AND U-value 0.8 — i.e., thermal and acoustic in one stack. For acoustic-only priorities, a double-glazed acoustic-laminated at lower cost is often the better choice.\u003c\/p\u003e\n\n\u003ch3\u003eWill this fit my existing frame?\u003c\/h3\u003e\n\u003cp\u003eAt 42-44mm overall, only thermally-broken aluminium and timber-aluminium composite frames with 70-90mm depth will accept it. Standard PVCu and older aluminium will need full frame replacement, not just reglazing. We strongly recommend an installer site visit before specifying — frame compatibility is the most common project blocker for acoustic triple.\u003c\/p\u003e\n\n\u003ch3\u003eDo I need acoustic trickle vents?\u003c\/h3\u003e\n\u003cp\u003eYes — Building Regs Approved Document F requires background ventilation, but standard trickle vents short-circuit the acoustic performance. Specify acoustic trickle vents (Rytons Aircore, Greenwood Acoustic, or equivalent) — typically R\u003csub\u003ew\u003c\/sub\u003e(C;C\u003csub\u003etr\u003c\/sub\u003e) ≥ 38 dB so they're not the weak link. Vent acoustic ratings are independent of glass acoustic ratings.\u003c\/p\u003e\n\n\u003ch3\u003eLocal-authority noise-grant compliance?\u003c\/h3\u003e\n\u003cp\u003eMost UK noise-mitigation grant schemes (around airports + major motorways) accept R\u003csub\u003ew\u003c\/sub\u003e ≥ 35 dB as the minimum specified glazing. R\u003csub\u003ew\u003c\/sub\u003e 44 dB exceeds this comfortably and qualifies for top-tier funding bands where applicable. We supply the test pack at no charge for grant applications.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on acoustic-PVB delamination (manufacturer's BS EN 14449 standard warranty). 10 years on argon retention to ≥80% of initial fill. Acoustic R\u003csub\u003ew\u003c\/sub\u003e performance is warranted at the certified test value at installation date — declining performance is not warrantable because it's typically a frame-seal or vent issue, not a glass issue.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853203202378,"sku":"TG-AC44-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853203235146,"sku":"TG-AC44-800x600","price":80.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853203267914,"sku":"TG-AC44-1000x800","price":133.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853203300682,"sku":"TG-AC44-1200x1000","price":199.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853203333450,"sku":"TG-AC44-1500x1200","price":299.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_104e02f2-d2b6-4852-a4c8-e6b512bd20f3.webp?v=1779007261"},{"product_id":"laminated-safety-glass-sealed-unit-bs-en-14449","title":"Laminated Safety Glass Sealed Unit (BS EN 14449)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe fragment-retention safety unit\u003c\/strong\u003e. A laminated double-glazed sealed unit (6.4mm laminated outer \/ 16mm argon cavity \/ 4mm clear inner) combines BS EN 14449 laminated-glass certification with BS EN 1279 sealed-unit construction — the right unit where safety glass is required, overhead glazing applies, or fragment retention matters more than the granular-shower behaviour of toughened.\u003c\/p\u003e\n\n\u003cp\u003e\"Laminated\" means two plies of glass bonded by a polyvinyl-butyral (PVB) interlayer. On impact, the glass cracks but stays bonded to the interlayer — fragments are held in place, not released as a shower. This is the opposite of toughened glass, which is impact-strong but breaks in one event into many granular fragments. Both are \"safety glass\" under Approved Document N; the right choice depends on the application.\u003c\/p\u003e\n\n\u003ch2\u003eLaminated vs toughened — when each wins\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eSpecify laminated when:\u003c\/strong\u003e overhead glazing (BS 5516 mandates fragment retention); balustrade or balcony glazing (fall-from-height risk); security applications (intruder forced entry); shop fronts (post-impact residual barrier matters); display cases \/ museum glazing; bath screens (no granular shower in wet\/bare-foot environments).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSpecify toughened when:\u003c\/strong\u003e domestic critical locations at low elevation (door sidelights, low windows); shower screens away from foot-traffic; where the impact requirement is Class 1(C)1 (highest grade — laminated typically Class 2(B)2 unless reinforced); where cost is dominant (toughened ~15-20% cheaper than equivalent laminated).\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e~26-28mm depending on laminated build\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e6.4mm laminated outer (3+3 with 0.38mm PVB) \/ 16mm argon \/ 4mm clear inner — optional low-E on face 3\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOuter-pane standard\u003c\/th\u003e\n\u003ctd\u003eBS EN 14449 (laminated glass for construction)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eImpact classification\u003c\/th\u003e\n\u003ctd\u003eBS EN 12600 Class 2(B)2 (pendulum drop 450mm, no penetration, fragments retained)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eFragment retention\u003c\/th\u003e\n\u003ctd\u003eYes — PVB interlayer holds broken-glass fragments in place\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverhead-glazing compliance\u003c\/th\u003e\n\u003ctd\u003eBS 5516 (fragment-retention requirement satisfied)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane, uncoated)\u003c\/th\u003e\n\u003ctd\u003e1.5 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (with low-E inner face 3)\u003c\/th\u003e\n\u003ctd\u003e1.2 W\/m²K — configurable\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.65\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~78%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSide benefits\u003c\/th\u003e\n\u003ctd\u003eAcoustic R\u003csub\u003ew\u003c\/sub\u003e ~34 dB (better than 4-16-4 symmetric DG); UV-blocking ~99% via PVB interlayer\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 14449, BS EN 12600, BS 5516 (overhead), Approved Document N\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservatory roofs and rooflights\u003c\/strong\u003e — BS 5516 mandates fragment retention overhead. Laminated outer + clear inner is the standard spec. (For combined safety-and-impact-Class-1, consider the \u003ca href=\"\/products\/triple-glazed-safety-toughened-laminated-unit\"\u003eTriple Glazed Safety flagship\u003c\/a\u003e.)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBalustrade glazing and Juliet balconies\u003c\/strong\u003e — fall-from-height risk drives the laminated requirement. BS 6180 (barriers in buildings) sets out the impact-test regime.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShop fronts and retail glazing\u003c\/strong\u003e — post-impact residual barrier matters for both customer safety and stock security.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDisplay cases and museum glazing\u003c\/strong\u003e — the PVB interlayer also blocks ~99% of UV, protecting contents from fading.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBath screens and shower enclosures in family bathrooms\u003c\/strong\u003e — laminated removes the wet-foot-on-granular-shower risk of toughened.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLight security applications\u003c\/strong\u003e — opportunistic-intruder forced entry is meaningfully slowed by laminated; the residual interlayer barrier holds glass in place even after multiple strikes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full safety-glazing decision tree, including the toughened-vs-laminated tradeoffs and the anti-bandit (BS EN 356 P-rated) upgrade path for higher-security applications, is on the \u003ca href=\"\/pages\/safety-security-glass\"\u003e\u003cstrong\u003esafety \u0026amp; security glass topical page\u003c\/strong\u003e\u003c\/a\u003e. For non-overhead critical locations where impact rating dominates the spec, the \u003ca href=\"\/products\/28mm-safety-toughened-double-glazed-unit\"\u003e28mm Safety Toughened flagship\u003c\/a\u003e is the cost-optimal choice.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are below. Dispatch 10-14 working days (lamination adds ~5 days to standard DG manufacturing). Custom sizes — including thicker PVB builds (1.52mm interlayer for higher security), heat-strengthened-plus-laminated combinations, and anti-bandit BS EN 356 P-rated upgrades — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with: UKCA mark, BS EN 1279 DoP for the sealed unit, BS EN 14449 laminated-glass certificate for the outer pane (interlayer thickness + PVB batch identity), BS EN 12600 impact classification, and a BS 5516 overhead-glazing compliance statement on request. For tender \/ commercial work, we supply a Letter of Conformance referencing the relevant standards bundle.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWhat's the difference between PVB and SGP interlayer?\u003c\/h3\u003e\n\u003cp\u003ePVB (polyvinyl butyral) is the standard interlayer — flexible, well-bonded, widely available. SGP (SentryGlas Plus, an ionoplast) is roughly 5× stiffer than PVB and 100× more impact-resistant. For balustrade and overhead applications with elevated post-failure load requirements, SGP-laminated is the upgrade — adds ~£40-60\/m² over PVB. Configure via the configurator.\u003c\/p\u003e\n\n\u003ch3\u003eWill laminated stop a burglar?\u003c\/h3\u003e\n\u003cp\u003eSlows them, doesn't stop them. Standard PVB-laminated glass is impact-tested for human-impact safety, not intruder resistance. For burglary-resistant glazing, specify BS EN 356 P-rated (P1A-P5A for projectile, P6B-P8B for manual attack). The configurator surfaces these as anti-bandit options — typically thicker PVB or multi-ply builds.\u003c\/p\u003e\n\n\u003ch3\u003eDoes laminated affect light transmittance?\u003c\/h3\u003e\n\u003cp\u003eMarginally. A 6.4mm PVB-laminated pane transmits ~88% of light (vs ~90% for monolithic 6mm). The cavity + inner pane drop that to ~78% overall. For low-iron variants (Pilkington Optiwhite laminated), light transmittance recovers to ~82% — useful for galleries and display cases where colour rendering matters.\u003c\/p\u003e\n\n\u003ch3\u003eCan I add low-E to a laminated unit?\u003c\/h3\u003e\n\u003cp\u003eYes. Soft-coat low-E on face 3 (the cavity-side face of the inner pane) is the standard low-E position for laminated DG. The configurator adds Planitherm Total+ for U=1.2 W\/m²K. Hard-coat (Pilkington K) can also be specified on the laminated outer pane during lamination — typically used where the unit must be toughened-laminated.\u003c\/p\u003e\n\n\u003ch3\u003eUV protection — how much actually?\u003c\/h3\u003e\n\u003cp\u003eStandard PVB blocks ~99% of UV-B and ~95% of UV-A — significantly better than monolithic glass (~30% UV-A block). For museum, gallery, archival, and high-value-textile applications, this is a side benefit worth specifying. Saflex Q-series and Trosifol UltraClear offer enhanced UV blocking at minimal premium.\u003c\/p\u003e\n\n\u003ch3\u003eAcoustic benefit?\u003c\/h3\u003e\n\u003cp\u003eYes — R\u003csub\u003ew\u003c\/sub\u003e ~34 dB for this build, vs ~30 dB for a symmetric 4-16-4 DG. The PVB interlayer adds modest viscoelastic damping. For acoustic-priority projects, the \u003ca href=\"\/products\/specialist-acoustic-laminated-glass-asymmetric-double-glazed-unit\"\u003eSpecialist Acoustic Laminated flagship\u003c\/a\u003e (8.8 + 4 asymmetric, acoustic-grade PVB) hits R\u003csub\u003ew\u003c\/sub\u003e 40 dB at modest premium.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on PVB delamination (BS EN 14449 manufacturer standard). 10 years on argon retention to ≥80% of initial fill. Impact-classification is warranted at the certified test value on the manufactured pane — long-term degradation (yellowing of older PVB, edge-seal water ingress) is excluded from the impact-class warranty.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853203431754,"sku":"DG-LAM-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853203464522,"sku":"DG-LAM-800x600","price":59.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853203497290,"sku":"DG-LAM-1000x800","price":98.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853203530058,"sku":"DG-LAM-1200x1000","price":147.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853203562826,"sku":"DG-LAM-1500x1200","price":220.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_f7d70d73-d655-41b8-9244-066ef43ebb50.webp?v=1779007262"},{"product_id":"44mm-premium-triple-glazed-krypton-low-e-unit","title":"44mm Premium Triple Glazed Unit (Krypton + Soft-Coat Low-E)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe Passivhaus spec — without the bespoke German lead time\u003c\/strong\u003e. A 44mm premium triple-glazed unit (4mm \/ 16mm krypton + soft-coat low-E \/ 4mm \/ 16mm krypton + soft-coat low-E \/ 4mm) delivers a centre-pane U-value of 0.5 W\/m²K and a whole-window U-value of 0.7-0.8 W\/m²K in a thermally-broken frame — meeting the Passivhaus Institut's strict 0.8 W\/m²K window requirement for cool-temperate climates.\u003c\/p\u003e\n\n\u003cp\u003eThis is the spec the Scandinavian and German new-build market has used as a baseline for two decades. In the UK, it appears in Passivhaus retrofits (EnerPHit), Future Homes Standard pilot projects, and any deep-retrofit where fabric heat-loss is being driven below 15 kWh\/m²·yr. It is the most thermally-efficient mainstream IGU available, and the spec heat-pump-led retrofits depend on to keep flow temperatures at 35-45°C.\u003c\/p\u003e\n\n\u003ch2\u003eWhy both krypton fills AND dual low-E coatings\u003c\/h2\u003e\n\u003cp\u003eEach thermal layer compounds. Krypton at 16mm in this unit's wider cavity gives ~10% additional benefit over argon (the cavity is just shallow enough that krypton still outperforms). Soft-coat low-E on faces 3 and 5 — the inner surfaces of each cavity — reflects long-wave radiant heat back into the warm side of each cavity. The dual-coating strategy means each cavity does roughly half the work, instead of single-coating loading all the thermal performance onto one face.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 16mm krypton \/ 4mm clear (Planitherm face 3) \/ 16mm krypton \/ 4mm clear (Planitherm face 5)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCavities\u003c\/th\u003e\n\u003ctd\u003e2 × 16mm krypton-filled (BS EN 1279-3 verified ≥90%)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bars\u003c\/th\u003e\n\u003ctd\u003e2 × warm-edge composite, black low-conductivity\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e0.5 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window in thermally-broken alu\/timber frame)\u003c\/th\u003e\n\u003ctd\u003e0.7-0.8 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.50 (slightly lower than standard triple — dual coating trade)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~70%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA++ (when fitted in a compliant Passivhaus frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~30 kg\/m² — confirm hinge \/ sash rating\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, PHI window certification compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePassivhaus and EnerPHit projects\u003c\/strong\u003e — Passivhaus Institut whole-window requirement is ≤ 0.8 W\/m²K for cool-temperate climates. This unit delivers it in a standard frame.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHeat-pump retrofits\u003c\/strong\u003e — ASHPs operate most efficiently at low flow temperatures (35-45°C). Premium triple cuts fabric heat loss enough that an ASHP can hold setpoint without bumping flow temperature into the high-COP penalty zone.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFuture Homes Standard pilot builds\u003c\/strong\u003e — the 2025+ FHS draft envelope targets whole-window U ≤ 0.8 W\/m²K. This spec is the cleanest path.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEPC band A targets\u003c\/strong\u003e — for landlords planning ahead of the proposed 2030 MEES B (or future C-ratchet), premium triple is the glazing spec that consistently scores band-A.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNorth-facing principal rooms in deep-retrofit projects\u003c\/strong\u003e where every kWh of fabric heat loss matters and the install budget can absorb the premium.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe whole-window thermal math, BFRC vs PHI certification, and a side-by-side payback analysis against A-rated double is on the \u003ca href=\"\/pages\/triple-glazing\"\u003e\u003cstrong\u003etriple glazing topical page\u003c\/strong\u003e\u003c\/a\u003e. For Building Regs Approved Document L compliance only (not Passivhaus), the lower-cost \u003ca href=\"\/products\/36mm-standard-triple-glazed-unit\"\u003e36mm Standard Triple Glazed Unit\u003c\/a\u003e is the practical choice.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below. Dispatch 10-14 working days (premium krypton + dual coating extends lead time vs standard triple). Custom sizes via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e — including Passivhaus-certified frames, oversized panes (\u0026gt;1500mm), and asymmetric panes for combined thermal-plus-acoustic stacks.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrame load note:\u003c\/strong\u003e at ~30 kg\/m² this unit is materially heavier than double glazing. Hinge capacity, frame reinforcement, and sash-balance specifications need to be checked. For a 1500 × 1200 unit, that's roughly 54 kg — outside the capacity of many budget PVCu profiles. Confirm with your frame supplier before specifying.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA-marked, BS EN 1279 compliant. PHI-certified component manufacturers carry a Passivhaus stamp — request this batch stamp at order for Passivhaus project documentation. The dual Planitherm coatings carry Saint-Gobain's batch certification. Krypton retention is warranted to ≥80% of initial fill at 10 years.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eIs the premium over standard triple worth it?\u003c\/h3\u003e\n\u003cp\u003eDepends on the energy strategy. For a heat-pump-led deep retrofit driving toward 15 kWh\/m²·yr fabric demand: yes — the 0.3 W\/m²K centre-pane reduction integrates over a heating season into measurable kWh savings. For Building Regs replacement on a 1980s extension: probably not — the standard triple does the regs job at ~70% of the cost.\u003c\/p\u003e\n\n\u003ch3\u003eWill my frame take this unit?\u003c\/h3\u003e\n\u003cp\u003eModern 70-90mm thermally-broken aluminium and timber-aluminium composite frames are designed for 44-48mm units. Older 60mm PVCu and most 1990s aluminium will not accept it — you'd be replacing the whole window assembly, not just reglazing. Send a frame profile photo to \u003ca href=\"\/pages\/contact-us\"\u003eour contact form\u003c\/a\u003e for compatibility advice before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eWhy is g-value lower than standard triple?\u003c\/h3\u003e\n\u003cp\u003eTwo soft-coat low-E layers vs one in a standard triple. Each coating reflects some short-wave solar plus most long-wave radiant. Two coatings reflect more solar — that's the price of the U-value improvement. For south-facing principal rooms in colder climates, the passive solar loss is real and worth modelling against the U-value win.\u003c\/p\u003e\n\n\u003ch3\u003eKrypton retention over 25 years?\u003c\/h3\u003e\n\u003cp\u003eIndustry standard is \u0026lt;1% per year under EN-1279-2 accelerated weathering. Over 25 years that's ~22% total. At ~78% krypton + 22% air, centre-pane U-value rises from 0.5 to ~0.55 W\/m²K — still well inside Passivhaus territory. Edge-seal failure is the real long-term risk (15-25 years), not krypton diffusion.\u003c\/p\u003e\n\n\u003ch3\u003ePassivhaus certification — what's actually required?\u003c\/h3\u003e\n\u003cp\u003ePHI window certification is on the whole-window assembly (frame + glass + spacer + installation method), not on the glass alone. This unit is a PHI-compatible component — fitted into a PHI-certified frame, the assembly can be PHI-certified. Glass-only certification is not a thing.\u003c\/p\u003e\n\n\u003ch3\u003eComparison with vacuum-insulated glazing (VIG)?\u003c\/h3\u003e\n\u003cp\u003eVIG (Pilkington Spacia, LandVac, FineoVacuum) offers similar U-values in a 6-8mm overall thickness — useful for heritage retrofits where slim DG can't deliver enough thermal performance. Cost is 3-5× higher per m². For mainstream new-build and major retrofit where rebate depth isn't constrained, premium triple is the cost-optimal route to Passivhaus thermals.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity. 10 years on krypton retention to ≥80% of initial fill. 5 years on each Planitherm coating (separate Saint-Gobain certifications per face). Whole-window Passivhaus performance is warranted on the frame manufacturer's terms — confirm with your frame supplier.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853203628362,"sku":"TG44-PREMKR-600x400","price":54.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853203661130,"sku":"TG44-PREMKR-800x600","price":108.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853203693898,"sku":"TG44-PREMKR-1000x800","price":179.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853203726666,"sku":"TG44-PREMKR-1200x1000","price":268.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853203759434,"sku":"TG44-PREMKR-1500x1200","price":402.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_b9d55c0d-89a0-4b10-be78-51ce1e018902.webp?v=1779007264"},{"product_id":"14mm-slim-krypton-conservation-double-glazed-unit","title":"14mm Slim Krypton Double Glazed Unit (Conservation)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eHeritage-aperture double glazing where rebate depth is the constraint\u003c\/strong\u003e. A 14mm slim krypton-filled sealed unit (4mm clear \/ 6mm krypton cavity with soft-coat low-E \/ 4mm clear) is the conservation-officer-friendly double-glazing spec — engineered for Georgian and Victorian timber sashes, listed-building consents, and conservation-area replacement where a 24mm or 28mm unit will not fit the original rebate.\u003c\/p\u003e\n\n\u003cp\u003eSlim double-glazed units exist for one reason: the original glazing rebate in a pre-1920s timber sash was cut for 4mm single glazing — typically 8-12mm deep. A standard 24mm modern unit simply will not seat in that rebate without re-cutting the sash (which most listed-building consents prohibit) or fitting bulky surface-mounted secondary glazing (which conservation officers usually reject on sightline grounds). Slim units squeeze a true argon-or-krypton-filled IGU into a 14mm overall depth — sometimes less — and let original joinery stay intact.\u003c\/p\u003e\n\n\u003ch2\u003eWhy krypton, not argon, in this build\u003c\/h2\u003e\n\u003cp\u003eCavity gas performance is a function of cavity depth. In a 16mm cavity (the standard 24mm unit) argon is optimal — krypton offers no further U-value benefit and costs five times more. Below 10mm, argon's convective performance degrades and krypton becomes the better insulator. At a 6mm cavity (this unit), krypton drops centre-pane U-value from ~2.0 (argon) to ~1.6 (krypton) — a meaningful 20% improvement at a cavity depth where every fraction of a watt matters.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e14mm (nominal — tolerance ±0.5mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 6mm krypton cavity \/ 4mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e≥90% krypton (BS EN 1279-3 verified)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black slim-profile (typ. 5-6mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.6 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window, sash + glass)\u003c\/th\u003e\n\u003ctd\u003e~1.9-2.1 W\/m²K depending on frame\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.63\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~78%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSightline \/ cavity-edge appearance\u003c\/th\u003e\n\u003ctd\u003e~12-15mm visible from outside (matches single-glazed sightline within heritage tolerance)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279 (parts 1-6), BS EN 673 (U-value), Historic England slim-DG guidance compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eListed buildings (Grade II, II*, I)\u003c\/strong\u003e where the conservation officer has accepted slim double glazing as a \"like-for-like\" replacement of failed single glazing.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservation area consents\u003c\/strong\u003e in cities like Bath, Edinburgh, Brighton, and Oxford where original sash sightlines are protected.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGeorgian, Regency, and Victorian timber sashes\u003c\/strong\u003e with original glazing rebates 8-14mm deep — fits without re-rebating.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHeritage shopfronts and ecclesiastical glazing\u003c\/strong\u003e where leaded-light, crown-glass, or stained-glass aesthetics must be preserved at the sightline.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperties in Article 4 direction areas\u003c\/strong\u003e where windows are subject to planning control and full-thickness DG would breach consent conditions.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eSlim double glazing's tradeoffs, conservation-officer evidence-pack templates, and the case for slim Krypton over secondary glazing are covered in depth on the \u003ca href=\"\/pages\/slim-double-glazing\"\u003e\u003cstrong\u003eslim double glazing topical page\u003c\/strong\u003e\u003c\/a\u003e — including a checklist for evidencing slim DG to a conservation officer.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are listed below. Each is dispatched 10-14 working days from order (slim-cavity krypton manufacturing is a specialist process — longer lead time than standard 24mm DG). Custom sizes — including arched-top, raked, leaded-effect overlay, and conservation-bar-compatible variants — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNote on listed-building consent:\u003c\/strong\u003e these units are manufactured to a specification accepted by most UK conservation officers under \"minimal intervention\" principles, but consent is always property-specific. We can supply a technical pack (cavity-depth diagram, gas-retention test data, BS EN 1279 DoP) for inclusion in your application — request via \u003ca href=\"\/pages\/contact-us\"\u003eour contact form\u003c\/a\u003e at order.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA-marked, BS EN 1279 compliant across all six parts. Krypton gas fill is verified per BS EN 1279-3 at initial fill ≥90% with annual loss \u0026lt;1% under EN-1279-2 accelerated weathering. Slim-cavity construction adds a 6th-part test for capillary water ingress at the warm-edge interface — every batch carries a hydrostatic pressure cycle stamp.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWill a conservation officer accept this?\u003c\/h3\u003e\n\u003cp\u003eUsually yes — slim DG is now widely accepted across UK local authorities under Historic England's \u003cem\u003eEnergy Efficiency and Historic Buildings\u003c\/em\u003e guidance (2018). Acceptance is property-specific: officers in Bath and Edinburgh are typically more conservative than rural authorities. The case is strongest when (a) the original single-glazed unit has failed, (b) the slim unit matches the original sightline within 2-3mm, and (c) you submit a manufacturer's spec sheet showing BS EN 1279 compliance. Pre-submission consultation with the officer is recommended.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this compare to secondary glazing?\u003c\/h3\u003e\n\u003cp\u003eSecondary glazing adds an internal pane in a separate frame, leaving the original glazing intact. It performs well thermally (U ~1.8 W\/m²K combined) and excellently acoustically (Rw up to 45 dB). But it's visible, adds maintenance complexity, and many conservation officers consider it less sympathetic than slim DG. Slim DG replaces the failed unit at the existing sightline. The right call depends on the property and the officer.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the cavity depth tolerance?\u003c\/h3\u003e\n\u003cp\u003e6mm nominal ± 0.5mm. Edge-seal compression during sealing introduces a small reduction. For a 14mm overall unit, this means the sash rebate needs at least 14.5mm depth with 2-3mm of clearance for fitting putty or beading — total 17mm minimum.\u003c\/p\u003e\n\n\u003ch3\u003eKrypton retention — does it leak out?\u003c\/h3\u003e\n\u003cp\u003eIndustry standard is \u0026lt;1% per year under EN-1279-2 accelerated weathering. Over 25 years that's \u0026lt;22% total loss — at 78% krypton + 22% air, centre-pane U-value rises from 1.6 to ~1.7 W\/m²K. The warm-edge spacer's gas-permeation barrier is the critical component; warranty is 10 years on krypton retention to 80% of initial fill.\u003c\/p\u003e\n\n\u003ch3\u003eCan I add laminated panes for acoustic or security?\u003c\/h3\u003e\n\u003cp\u003eYes via configurator — 6.4mm acoustic laminated outer with 4mm clear inner adds about 2mm to overall thickness (16mm total). This is the recommended combo for slim DG in conservation areas backing onto noisy streets. Rw improves to ~36-38 dB while preserving the heritage sightline.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the price premium vs standard 24mm DG?\u003c\/h3\u003e\n\u003cp\u003eRoughly 40-50%. Krypton fill alone is ~5× the cost of argon; the slim-cavity manufacturing process adds further premium because edge-seal tolerances are tighter and yield rates are lower. The configurator surfaces the live per-m² rate so you can compare against the standard 24mm A-rated double.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on krypton retention to ≥80% of initial fill. 5 years on the Planitherm soft-coat (Saint-Gobain batch certification). Listed-building installations are warranted on the same terms — installation must be by a competent person familiar with heritage joinery.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853203857738,"sku":"DG14-SLIMKR-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853203890506,"sku":"DG14-SLIMKR-800x600","price":72.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853203923274,"sku":"DG14-SLIMKR-1000x800","price":119.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853203956042,"sku":"DG14-SLIMKR-1200x1000","price":179.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853203988810,"sku":"DG14-SLIMKR-1500x1200","price":268.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_51f79282-bd42-42e4-98b1-9e82f9e659e8.webp?v=1779007266"},{"product_id":"triple-glazed-safety-toughened-laminated-unit","title":"Triple Glazed Safety Unit (Toughened + Laminated)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe triple-glazed unit for critical locations and overhead glazing\u003c\/strong\u003e. A triple-glazed sealed unit with toughened outer and inner panes plus a laminated middle pane combines Approved Document N safety compliance with Approved Document L thermal performance — and adds the BS 5516 overhead-glazing safety requirement that vanilla toughened triple cannot meet.\u003c\/p\u003e\n\n\u003cp\u003eFor most replacement windows, a 28mm toughened double is the standard safety spec. But where the application demands triple-glazed thermal performance AND involves overhead glazing (conservatory roof bars, atria, balcony glazing, large-span domestic rooflights), the safety regime escalates: both BS 5516 (overhead glazing) and Approved Document N (impact safety) need to be satisfied at once. This flagship is engineered for that intersection.\u003c\/p\u003e\n\n\u003ch2\u003eWhy toughened + laminated, not toughened alone\u003c\/h2\u003e\n\u003cp\u003eToughened glass is impact-strong but failure-mode-dangerous overhead. When toughened breaks, it shatters into thousands of granular fragments — relatively safe at low elevation, but a hazardous shower from height. BS 5516 (overhead glazing code of practice) requires that overhead panes either be laminated (so fragments stay in the interlayer) or be supported by a secondary catchment system.\u003c\/p\u003e\n\n\u003cp\u003eThis unit places the laminated pane as the middle pane in the triple stack. The outer and inner toughened panes provide impact strength; if both break, the laminated middle layer holds glass fragments in place — meeting BS 5516 without compromising the impact-rated outer\/inner faces.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e36-40mm depending on laminated mid-pane spec\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm toughened \/ 12mm argon \/ 6.4mm laminated middle (3+3 with 0.38mm PVB) \/ 12mm argon \/ 4mm toughened\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCavities\u003c\/th\u003e\n\u003ctd\u003e2 × 12mm argon-filled (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOuter\/Inner impact classification\u003c\/th\u003e\n\u003ctd\u003eBS EN 12150 + BS EN 12600 Class 1(C)1\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eMiddle pane standard\u003c\/th\u003e\n\u003ctd\u003eBS EN 14449 laminated (PVB interlayer)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverhead-glazing compliance\u003c\/th\u003e\n\u003ctd\u003eBS 5516 (laminated middle satisfies fragment-retention requirement)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane, with low-E)\u003c\/th\u003e\n\u003ctd\u003e0.8 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (uncoated)\u003c\/th\u003e\n\u003ctd\u003e1.0 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.54\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~70%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~35 kg\/m² (heavy — confirm structural frame capacity)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 12150, BS EN 14449, BS 5516, Approved Document N, Approved Document L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservatory roof bars and triangular vents\u003c\/strong\u003e where overhead glazing must comply with BS 5516 AND the room is thermally connected to the dwelling (so Part L applies).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLarge-span rooflights\u003c\/strong\u003e in domestic extensions — typically anything \u0026gt;2m² overhead requires laminated under BS 5516.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAtrium glazing and pitched balcony screens\u003c\/strong\u003e where falls from height create a foreseeable risk.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFrench doors and floor-to-ceiling glazing in critical locations\u003c\/strong\u003e needing both impact safety (Class 1(C)1) AND triple-pane thermal performance for Passivhaus\/EnerPHit specs.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBath-screen glazing in high-traffic family bathrooms\u003c\/strong\u003e — where both fragment retention and impact resistance matter at the door edge.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSchool and hospital glazing\u003c\/strong\u003e in critical locations under public-sector safety procurement frameworks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe full safety-glazing decision tree, including the laminated-vs-toughened tradeoffs and the anti-bandit upgrade path, is on the \u003ca href=\"\/pages\/safety-security-glass\"\u003e\u003cstrong\u003esafety \u0026amp; security glass topical page\u003c\/strong\u003e\u003c\/a\u003e. For non-overhead critical locations where double glazing thermal is adequate, the simpler \u003ca href=\"\/products\/28mm-safety-toughened-double-glazed-unit\"\u003e28mm Safety Toughened Double Glazed Unit\u003c\/a\u003e is the cost-optimal choice.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are below. Dispatch 14-18 working days (toughening + lamination + triple assembly is a sequential multi-stage process). Custom sizes — including arched-top rooflight units, shaped balustrade panels, and Class 2(B)2 upgraded impact-rated builds — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrame load note:\u003c\/strong\u003e at ~35 kg\/m² this unit is roughly 75% heavier than a 24mm DG. Confirm structural-frame capacity, fixing-bolt spec, and hinge ratings. For overhead-glazing applications, structural-engineer sign-off on the supporting framework is usually required.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with: UKCA mark, BS EN 1279 Declaration of Performance, BS EN 12150 toughening stamp permanently etched in two corners, BS EN 14449 laminated-glass certificate on the middle pane, and a BS 5516 overhead-glazing compliance statement on request. Heat-soak testing (BS EN 14179) on the toughened panes is available as a build option for large-span overhead applications where spontaneous breakage risk warrants it.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eIs laminated alone good enough overhead?\u003c\/h3\u003e\n\u003cp\u003eLaminated meets BS 5516 fragment-retention on its own — but it doesn't necessarily meet Approved Document N impact classification. For critical locations under or near doors, a Class 1(C)1 impact rating is required. This flagship's outer\/inner toughened faces deliver that; the laminated middle adds the overhead fragment-retention. Both standards satisfied in one stack.\u003c\/p\u003e\n\n\u003ch3\u003eWhy not laminated outer AND inner?\u003c\/h3\u003e\n\u003cp\u003eYou could specify that — and it would meet both standards with a different tradeoff (slightly higher Rw acoustic, slightly lower impact rating, ~£15-20\/m² more). The toughened-outer-toughened-inner-laminated-middle build is the cost-optimal route for the typical critical-location-plus-overhead intersection. The configurator surfaces both options if you want to A\/B them.\u003c\/p\u003e\n\n\u003ch3\u003eCan the middle pane be heat-strengthened instead of laminated?\u003c\/h3\u003e\n\u003cp\u003eHeat-strengthened is between annealed and toughened in strength — it has a wider fragment pattern than toughened but doesn't reliably retain fragments. It does not satisfy BS 5516 overhead-glazing requirements. The PVB-laminated middle is the standards-compliant choice.\u003c\/p\u003e\n\n\u003ch3\u003eSpontaneous breakage with toughened — risk?\u003c\/h3\u003e\n\u003cp\u003eNickel-sulphide inclusion-driven spontaneous breakage occurs at roughly 1 per 8 tonnes of float feedstock. For large-span overhead applications (\u0026gt;4m² rooflights, balustrade-adjacent), specify heat-soak-tested toughened (BS EN 14179) — adds ~£8\/m² and reduces NiS risk by \u0026gt;99%. For most domestic-scale critical locations, untreated toughened is the standard.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this fit in a conservatory roof?\u003c\/h3\u003e\n\u003cp\u003eModern aluminium conservatory roof systems (e.g., Eurocell Skyroom, Ultraframe Livinroof) are profiled for 28-40mm units. Confirm with the system supplier — most accept 36-40mm. Older PVCu conservatory roofs may need profile upgrade or full re-roof.\u003c\/p\u003e\n\n\u003ch3\u003eBuilding Control sign-off?\u003c\/h3\u003e\n\u003cp\u003eLocal Authority Building Control or Approved Inspectors will check that critical-location glazing meets Approved Document N (impact) and overhead glazing meets BS 5516 (fragment retention). The DoP and impact-class certificate that ship with each unit are typically sufficient for sign-off. We can supply Letter of Conformance for tender \/ commercial projects.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity. 10 years on argon retention to ≥80% of initial fill. 10 years on PVB delamination (BS EN 14449). Toughened pane integrity is a manufacturer's lifetime warranty against in-stock defect — spontaneous breakage from NiS inclusion is excluded unless heat-soak-tested is specified at order.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853204054346,"sku":"TG-SAFTL-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853204087114,"sku":"TG-SAFTL-800x600","price":88.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853204119882,"sku":"TG-SAFTL-1000x800","price":147.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853204152650,"sku":"TG-SAFTL-1200x1000","price":220.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853204185418,"sku":"TG-SAFTL-1500x1200","price":330.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_cbb6e68f-bcbb-4c8e-9f14-92d931972e83.webp?v=1779007268"},{"product_id":"triple-glazed-conservation-krypton-slim-cavity-unit","title":"Triple Glazed Conservation Unit (Krypton, Slim Cavity)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eTriple-glazed thermal performance in a conservation-friendly slim envelope\u003c\/strong\u003e. A 26mm triple-glazed sealed unit (4mm clear \/ 8mm krypton \/ 4mm clear with soft-coat low-E \/ 8mm krypton \/ 4mm clear with soft-coat low-E) delivers a centre-pane U-value of 0.9 W\/m²K in an overall depth that fits many heritage timber sash rebates where the standard 36mm triple cannot.\u003c\/p\u003e\n\n\u003cp\u003eThis is a niche product engineered for a specific intersection: heritage and conservation apertures where the conservation officer accepts slim double-glazing in principle, but the building physics ask for triple-pane performance — typically Passivhaus-EnerPHit retrofits in Grade II listed Victorian and Edwardian properties, or deep-retrofit projects in conservation-area townhouses where heritage joinery is being conserved alongside fabric-first energy upgrades.\u003c\/p\u003e\n\n\u003ch2\u003eWhy krypton, and why 8mm cavities\u003c\/h2\u003e\n\u003cp\u003eCavity gas performance is a function of cavity depth. In a 16mm cavity (standard 24mm DG), argon is optimal — krypton offers no further U-value benefit and costs five times more. Below 10mm, argon's convective performance degrades and krypton becomes the better insulator. At 8mm cavities (this unit), krypton is the only fill that delivers meaningful insulation: argon at 8mm gives ~1.4 W\/m²K centre-pane in a triple stack; krypton drops that to ~0.9.\u003c\/p\u003e\n\n\u003cp\u003eTwo 8mm krypton cavities at 26mm total overall is a precise engineering trade. Smaller cavities sacrifice convective insulation; larger cavities push the overall thickness beyond the conservation-aperture limit. 8mm is the cavity depth that the krypton-vs-argon curve crosses over and where slim-cavity edge-seal manufacturing yield is still acceptable.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e26mm (nominal — tolerance ±0.5mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 8mm krypton \/ 4mm clear (Planitherm face 3) \/ 8mm krypton \/ 4mm clear (Planitherm face 5)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCavities\u003c\/th\u003e\n\u003ctd\u003e2 × 8mm krypton-filled (BS EN 1279-3 verified ≥90%)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bars\u003c\/th\u003e\n\u003ctd\u003e2 × warm-edge slim composite (typ. 6mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e0.9 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window, heritage timber sash)\u003c\/th\u003e\n\u003ctd\u003e1.4-1.6 W\/m²K depending on frame condition\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.52\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~71%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSightline \/ cavity-edge appearance\u003c\/th\u003e\n\u003ctd\u003e~22-24mm visible — wider than slim DG, narrower than standard triple\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e~30 kg\/m² — confirm sash-cord \/ pulley load before specifying for original sashes\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279 (parts 1-6), BS EN 673, Historic England slim-DG guidance compatible (case-by-case)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eListed-building EnerPHit retrofits\u003c\/strong\u003e — Passivhaus-Institut retrofit standard wants whole-window U ≤ 1.05 W\/m²K. This unit gets close in a heritage sash; the alternative (full sash replacement to modern frame) is rarely consented.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservation-area deep retrofit\u003c\/strong\u003e — particularly Article 4 direction areas in inner London, Bath, Edinburgh, Brighton, where sightlines are protected but EPC targets force fabric upgrade.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEdwardian and late-Victorian timber sashes\u003c\/strong\u003e with original glazing rebates 24-28mm deep — too shallow for standard triple, too valuable thermally for slim DG to suffice.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eListed-building heat-pump retrofits\u003c\/strong\u003e — ASHPs work best at low flow temperatures (35-45°C), which requires lower fabric heat loss than slim DG alone provides.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperty-specific officer-approved alternatives to secondary glazing\u003c\/strong\u003e — where the conservation officer has rejected secondary glazing on sightline or maintenance-access grounds.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor shallower 14mm conservation apertures, the \u003ca href=\"\/products\/14mm-slim-krypton-conservation-double-glazed-unit\"\u003e\u003cstrong\u003e14mm Slim Krypton Double Glazed Unit (Conservation) flagship\u003c\/strong\u003e\u003c\/a\u003e is the appropriate spec. For modern apertures where 36mm triple fits without conservation constraints, the \u003ca href=\"\/products\/36mm-standard-triple-glazed-unit\"\u003e\u003cstrong\u003e36mm Standard Triple Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e is dramatically cheaper. This 26mm slim-triple is specifically for the heritage-aperture-plus-deep-retrofit intersection.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below — all sized to fit common heritage sash apertures. Dispatch 21-28 working days (slim-cavity krypton-filled triple is the most specialist build in the range — manufacturing yield is lower, lead time longer). Custom sizes — including narrow-tall sash proportions (3:1 height-to-width), arched-top apertures, and bespoke sightline matching for officer approvals — are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNote on listed-building consent:\u003c\/strong\u003e conservation officer acceptance of slim triple is more property-specific than acceptance of slim double. The case is strongest when (a) the existing glazing has failed beyond viable repair, (b) the slim-triple sightline can be matched within 3-4mm of the original, and (c) the property's energy performance is a stated planning consideration (e.g., MEES enforcement risk for a listed-building landlord). Pre-submission consultation with the conservation officer is essential. We supply a technical evidence pack on request.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA-marked, BS EN 1279 compliant across all six parts. Krypton gas fills (both cavities) verified per BS EN 1279-3 at initial fill ≥90% with annual loss \u0026lt;1% under EN-1279-2 accelerated weathering. Slim-cavity construction adds an additional hydrostatic-pressure-cycle stamp per batch. PHI-component certification is available for EnerPHit projects — request at order.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow is this different from the 14mm slim-DG conservation unit?\u003c\/h3\u003e\n\u003cp\u003eDifferent aperture, different physics. The 14mm slim DG fits original Georgian \/ early-Victorian sashes (8-14mm rebates); the 26mm slim triple needs at least a 28mm rebate, which is typical of Edwardian and very-late-Victorian timber sashes, or sashes that have been previously rebated-out. The slim triple is a deeper thermal upgrade — U=0.9 vs U=1.6 — but at significantly higher cost and longer lead time.\u003c\/p\u003e\n\n\u003ch3\u003eWill my sash take a 30 kg\/m² unit?\u003c\/h3\u003e\n\u003cp\u003eSash-cord and balance-pulley systems are the limiting factor on original timber sashes. A 600 × 1200 mm unit at this weight is ~22 kg per pane — within most original sash balance-weight specifications. A 1500 × 1200 mm unit at 54 kg often exceeds original counterweight capacity and may need a sash-spring conversion or steel-balance retrofit. Confirm with your joiner before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eConservation officer evidence — what do I need?\u003c\/h3\u003e\n\u003cp\u003eTypically: (1) photographs of the existing glazing showing failure mode, (2) elevations showing the slim-triple sightline overlaid on the original, (3) BS EN 1279 Declaration of Performance, (4) krypton fill certificate, (5) a SAP \/ RdSAP report showing the projected EPC improvement. We supply items 3-4 directly; items 1-2-5 are the homeowner \/ architect's responsibility. Pre-submission consultation is recommended.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the cost premium vs slim DG?\u003c\/h3\u003e\n\u003cp\u003eApproximately 60-80% more, depending on size. Triple-pane krypton-filled construction at slim cavities is the most specialist build in mainstream IGU manufacturing — yields are lower, edge-seal tolerances tighter, and only a handful of UK manufacturers can produce this spec at scale. For most heritage applications, slim DG remains the cost-optimal choice; this unit is for projects where deep-retrofit thermals are the explicit goal.\u003c\/p\u003e\n\n\u003ch3\u003eKrypton retention — 25-year outlook?\u003c\/h3\u003e\n\u003cp\u003eIndustry standard is \u0026lt;1% per year under EN-1279-2 accelerated weathering, in both cavities independently. Over 25 years that's ~22% loss per cavity — at 78% krypton + 22% air, centre-pane U-value rises from 0.9 to ~1.05 W\/m²K. Edge-seal failure typically arrives first (15-25 years) and is the dominant failure mode rather than gas diffusion.\u003c\/p\u003e\n\n\u003ch3\u003eCan it be heat-soaked \/ toughened?\u003c\/h3\u003e\n\u003cp\u003eOuter faces can be toughened on order — adds Class 1(C)1 impact rating if needed for critical-location heritage glazing (e.g., low-level sashes within 800mm of floor). The inner laminated pane option (for overhead heritage glazing, rare but specified for some chapel\/ecclesiastical work) is also configurable.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on krypton retention to ≥80% of initial fill, per cavity. 5 years on each Planitherm coating. Heritage installations are warranted on the same terms — installation must be by a competent joiner familiar with sash counterbalance systems and conservation-grade glazing methods.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61853953818954,"sku":"TG-CONSKR-600x400","price":54.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61853953851722,"sku":"TG-CONSKR-800x600","price":108.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61853953884490,"sku":"TG-CONSKR-1000x800","price":179.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61853953917258,"sku":"TG-CONSKR-1200x1000","price":268.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61853953950026,"sku":"TG-CONSKR-1500x1200","price":402.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_5ee617f9-b89f-46fb-bb72-b185f90de41d.webp?v=1779018548"},{"product_id":"saint-gobain-bioclean-self-cleaning-coastal-unit","title":"Saint-Gobain Bioclean Self-Cleaning Coastal Unit (28mm)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eSelf-cleaning specified for the coast\u003c\/strong\u003e. A 28mm double-glazed sealed unit with a Saint-Gobain Bioclean self-cleaning outer pane and a Planitherm Total+ Low-E inner pane, argon-filled, optimised for coastal aspects where salt film, sea-spray mineral deposits, and gull-droppings dominate the cleaning burden. Bioclean is Saint-Gobain's pyrolytic titanium-dioxide self-cleaning coating — comparable to Pilkington Activ in mechanism, with marginally better field-test performance in salt-exposed conditions.\u003c\/p\u003e\n\n\u003cp\u003eThe performance edge in coastal conditions comes from two things: a slightly more hydrophilic surface profile (water sheets faster and more evenly, carrying salt deposits with it) and a tighter TiO₂ crystallinity that resists the etching effect of dried salt residue better than older photocatalytic coatings. The difference is modest on paper but meaningful in field service — coastal homes that switched from standard low-E to Bioclean report 50-70% reduction in salt-spot cleaning frequency.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm Saint-Gobain Bioclean outer (TiO₂ coating face 1) \/ 20mm argon cavity \/ 4mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOuter coating\u003c\/th\u003e\n\u003ctd\u003eSaint-Gobain Bioclean — pyrolytic titanium dioxide, optimised crystalline structure for coastal salt-film conditions\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.1 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.61\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~77%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA (in compliant frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSelf-cleaning activation\u003c\/th\u003e\n\u003ctd\u003eUV-A daylight; coastal field-test performance optimised\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSalt-spray resistance\u003c\/th\u003e\n\u003ctd\u003eBS EN ISO 9227 — 720+ hours without coating degradation\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, Saint-Gobain Bioclean technical datasheet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoastal and marine-exposed homes\u003c\/strong\u003e — properties within 5 miles of the UK coast where sea-spray and salt film are the dominant cleaning issue. Bioclean's salt-rinse performance edges out Activ in this aspect.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEstuary, harbour, and coastal-town properties\u003c\/strong\u003e — Whitstable, Brighton, Sandwich, Padstow, Aberdeen, Whitley Bay, and similar postcodes where windows develop salt streaks within days of cleaning.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoastal-aspect upper-storey windows\u003c\/strong\u003e — first-floor and dormer windows where cleaning access is awkward and salt deposits accumulate fastest on south- or west-facing aspects (prevailing wind direction).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoastal conservatories and orangeries\u003c\/strong\u003e — sea-front conservatory roof and side panels where the cleaning frequency is otherwise weekly. Bioclean reduces this to 4-6 weekly intervals.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoastal commercial and rental property\u003c\/strong\u003e — facilities-management cost reduction in coastal hotels, holiday lets, beach huts converted to permanent dwellings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor non-coastal self-cleaning applications, the \u003ca href=\"\/products\/pilkington-activ-self-cleaning-double-glazed-unit\"\u003e\u003cstrong\u003ePilkington Activ Self-Cleaning Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e is the dominant UK spec and slightly cheaper. The \u003ca href=\"\/pages\/self-cleaning-glass\"\u003e\u003cstrong\u003eself-cleaning glass topical page\u003c\/strong\u003e\u003c\/a\u003e walks the Activ-vs-Bioclean decision criteria in depth. For standard A-rated double without coastal optimisation, see the \u003ca href=\"\/products\/28mm-low-e-a-rated-double-glazed-unit\"\u003e\u003cstrong\u003e28mm Low-E A-Rated Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below. Dispatch 7-10 working days from order. Bioclean outer pane adds £35\/m² flat over the equivalent uncoated Low-E build — same uplift as Activ; the additional manufacturing controls for the coastal-optimised coating are absorbed in Saint-Gobain's wholesale supply. The configurator routes custom sizes via the same per-m² rate.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance, Saint-Gobain Bioclean outer-pane authentication certificate (sealed unit identifies coated pane orientation), argon-fill certificate, Planitherm low-E coating identification, salt-spray resistance certificate per BS EN ISO 9227 (720+ hours without coating degradation), and a Letter of Conformance referencing the Saint-Gobain Bioclean coastal-application technical datasheet. For commercial specification sheets, we supply Saint-Gobain's coastal-field-test report on request.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow is Bioclean actually different from Activ in coastal use?\u003c\/h3\u003e\n\u003cp\u003eBoth are pyrolytic titanium-dioxide pyrolytic coatings — same family of self-cleaning chemistry. Bioclean has a marginally more hydrophilic surface profile (contact angle ~15° vs Activ's ~20°) which means water sheets faster, carrying salt deposits in the runoff before they can dry into spots. Bioclean's TiO₂ crystallinity is also tuned for resistance to dried salt etching. In Saint-Gobain's own field tests on coastal Cornish properties, Bioclean delivered 30% better salt-rinse performance vs equivalent Activ over 24 months. Pilkington disputes the test methodology; we report what the published data say.\u003c\/p\u003e\n\n\u003ch3\u003eIf I'm 10+ miles from the coast, does Bioclean buy me anything?\u003c\/h3\u003e\n\u003cp\u003eNo — at that range, salt deposition is negligible. For inland aspects, the Activ flagship is the right call (very similar performance, slightly lower price). The Bioclean spec earns its premium only where salt film is the dominant cleaning issue, which is coastal-band exposure.\u003c\/p\u003e\n\n\u003ch3\u003eWhat about gull droppings — coastal area's other big issue?\u003c\/h3\u003e\n\u003cp\u003eBioclean's photocatalytic effect breaks down gull (and pigeon) droppings the same way Activ does — the organic content is oxidised by the TiO₂ + UV reaction, then rinsed away. Gull droppings are dominated by uric acid which is more aggressive than smaller-bird droppings and can etch glass if left for weeks. Bioclean accelerates the breakdown — typically a fresh dropping is cleared within 4-7 days on a south-facing aspect, vs 14-21 days on standard glass.\u003c\/p\u003e\n\n\u003ch3\u003eWill it work behind a balcony or other shaded aspect?\u003c\/h3\u003e\n\u003cp\u003eYes — needs UV-A daylight, not direct sunlight. North-facing and balcony-shaded aspects still receive enough UV-A for the photocatalytic cycle, just slower. Coastal Bioclean shaded performance is typically half-rate vs full-sun south-facing aspects — still substantially better than no self-cleaning glass.\u003c\/p\u003e\n\n\u003ch3\u003eCleaning products to avoid?\u003c\/h3\u003e\n\u003cp\u003eNo silicone glass treatments (Rain-X and similar). No abrasive cloths. No vinegar-based cleaners. If you do clean externally, plain water with a soft sponge. Most coastal Bioclean owners switch to water-only cleaning within the first year — detergent residues interrupt the self-cleaning cycle and are unnecessary given the photocatalytic action handles the dirt.\u003c\/p\u003e\n\n\u003ch3\u003eLead time and warranty?\u003c\/h3\u003e\n\u003cp\u003e7-10 working days dispatch. 10-year warranty on edge-seal integrity, argon retention, and Low-E inner-pane performance. The Saint-Gobain Bioclean outer coating is covered by Saint-Gobain's own 10-year coastal-performance warranty (passed through to end-user via our supply chain). Salt-spray resistance is guaranteed to BS EN ISO 9227 720-hour minimum, with documented field performance to 5+ years in service.\u003c\/p\u003e\n\n\u003ch3\u003eCan I get Bioclean in triple-glazed?\u003c\/h3\u003e\n\u003cp\u003eYes — configurable via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e. Bioclean outer + dual Planitherm Low-E + dual argon + 36mm or 44mm overall — coastal-spec triple glazing for premium new-build coastal homes. Lead time extends to 14-21 working days for triple-Bioclean.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855200477514,"sku":"DG28-BIOCL-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855200510282,"sku":"DG28-BIOCL-800x600","price":76.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855200543050,"sku":"DG28-BIOCL-1000x800","price":126.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855200575818,"sku":"DG28-BIOCL-1200x1000","price":189.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855200608586,"sku":"DG28-BIOCL-1500x1200","price":283.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_878789ae-bb6b-4801-835f-f48e2a82be70.webp?v=1779039912"},{"product_id":"32mm-triple-glazed-mid-thickness-retrofit-unit","title":"32mm Triple Glazed Unit (Mid-Thickness Retrofit)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe 2010-2020 frame sweet spot\u003c\/strong\u003e. A 32mm triple-glazed sealed unit (4mm clear \/ 10mm argon \/ 4mm clear with planitherm soft-coat \/ 10mm argon \/ 4mm clear) hits the middle of the cavity-depth tradeoff: enough cavity volume for ~0.9 W\/m²K centre-pane U-value, thin enough to drop into the 32mm rebate that dominated UK PVCu replacement frames in the 2010-2020 decade.\u003c\/p\u003e\n\n\u003cp\u003e32mm rebates became the unofficial UK standard around 2010 when frame manufacturers started shipping rebates sized for \"future-proof double or current-spec triple\". By 2015, most PVCu replacement frames left the factory with 32mm sash rebates. That means there are roughly 6-8 million UK homes whose current frame can accept a 32mm triple unit without rebate-routing or full frame replacement. This flagship is built for that retrofit market.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e32mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 10mm argon \/ 4mm clear with Planitherm Total+ soft-coat (face 3) \/ 10mm argon \/ 4mm clear with Planitherm Total+ soft-coat (face 5)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon, both cavities (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black — twin spacers\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e0.9 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window, PVCu frame)\u003c\/th\u003e\n\u003ctd\u003e~1.2 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.50\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~71%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA or A+ (in compliant frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSound reduction (Rw)\u003c\/th\u003e\n\u003ctd\u003e~34 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, BS EN 12758\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2010-2020 PVCu replacement frames with 32mm-rebated sashes\u003c\/strong\u003e — the dominant decade for UK replacement glazing. Most homes with frames replaced in this window have rebates ready for 32mm triple.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMid-spec new-build extensions and loft conversions\u003c\/strong\u003e where the frame brief specified \"32mm rebate, triple-capable\" — common with Veka, Liniar, Eurocell, and Rehau profiles.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eA+ WER target without paying 36-44mm prices\u003c\/strong\u003e — the 32mm build crosses the A\/A+ threshold on most frame profiles, giving a meaningful EPC uplift over A-rated double glazing.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApproved Document L1A new-build compliance\u003c\/strong\u003e — Part L1A's tighter U-value targets are met cleanly with 32mm triple (1.2 W\/m²K whole-window beats the 1.4 target with headroom).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMEES C-rating compliance for landlords pre-2028\u003c\/strong\u003e — upgrading to 32mm triple typically lifts an EPC by 8-12 points depending on baseline.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor 28mm-rebated frames (typically 2002-2010 vintage), the \u003ca href=\"\/products\/28mm-triple-glazed-slim-rebate-retrofit-unit\"\u003e\u003cstrong\u003e28mm Triple Glazed Slim Rebate Retrofit\u003c\/strong\u003e\u003c\/a\u003e is the right call. For 36mm-rebated new builds, the \u003ca href=\"\/products\/36mm-standard-triple-glazed-unit\"\u003e\u003cstrong\u003e36mm Standard Triple Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e gives more cavity volume for marginally better thermals. The \u003ca href=\"\/pages\/triple-glazing\"\u003e\u003cstrong\u003etriple-glazing topical page\u003c\/strong\u003e\u003c\/a\u003e walks the cavity-depth math in detail.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are listed below. Each is dispatched 10-14 working days from order. Custom rectangular and shaped variants are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e. Trade accounts: log in for tiered volume pricing.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance with dual-cavity argon-fill certificate (both cavities tested per BS EN 1279-3), dual-surface low-E coating identification (faces 3 and 5), and Letter of Conformance for BS EN 673 \/ BS EN 410 \/ BS EN 12758. For Building Regs Part L1A or L1B sign-off, the supplied centre-pane U-value certificate plus the frame's whole-window calculation is sufficient evidence.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow do I confirm my frame is 32mm-rebated?\u003c\/h3\u003e\n\u003cp\u003eCarefully remove the inner glazing bead from one casement. Measure the rebate depth (the slot the unit sits in) with calipers. 32mm rebate accepts a 32mm unit with the standard 3mm clearance \/ sealant margin. If the rebate measures 28mm, see the 28mm slim-rebate flagship. If 36mm or more, see the 36mm standard or 44mm premium triple flagships.\u003c\/p\u003e\n\n\u003ch3\u003e32mm vs 36mm — is the difference worth the price step?\u003c\/h3\u003e\n\u003cp\u003eU-value: 32mm triple = 0.9 W\/m²K vs 36mm triple = 0.7 W\/m²K. The 36mm unit delivers ~20% better thermals because the wider cavities allow more convection-resistant gas volume. For most retrofits the 32mm is the right call (no frame swap needed). For new builds where the rebate is chosen at frame-spec time, 36mm is the better long-term spec.\u003c\/p\u003e\n\n\u003ch3\u003eWill the heavier weight stress my frame hinges?\u003c\/h3\u003e\n\u003cp\u003eTriple glazing weighs ~30 kg\/m² vs double's ~20 kg\/m². A typical 1200×1000 casement carries ~36 kg of triple vs ~24 kg of double. Most 2010+ UK casement hinges are rated for 30+ kg per leaf with a single pair, 50+ kg with twin pairs. Older or budget hinges may need upgrading — check manufacturer data before ordering oversize units.\u003c\/p\u003e\n\n\u003ch3\u003eSun-facing rooms — will I lose solar gain?\u003c\/h3\u003e\n\u003cp\u003eA small amount, yes. The 32mm triple's g-value is ~0.50 vs a 28mm Low-E double's ~0.62. In south-facing rooms that means modestly less free winter solar gain. For climates where solar overheating is the bigger summer issue, that's actually a benefit. For passive-house design where winter solar gain is engineered into the heating strategy, this needs balancing against the thermal-envelope improvement.\u003c\/p\u003e\n\n\u003ch3\u003eAcoustic uplift over double?\u003c\/h3\u003e\n\u003cp\u003eRw ~34 dB for the 32mm triple vs ~30 dB for a 28mm Low-E double — a 4 dB improvement, perceptible but not transformative. The twin cavity helps low-frequency noise. For serious acoustic problems (railway lines, A-roads, flight paths) see the \u003ca href=\"\/products\/triple-glazed-acoustic-unit-44db-rw\"\u003eTriple Glazed Acoustic Unit (44 dB Rw)\u003c\/a\u003e with PVB interlayer.\u003c\/p\u003e\n\n\u003ch3\u003eLead time and warranty?\u003c\/h3\u003e\n\u003cp\u003e10-14 working days dispatch. 10-year warranty on edge-seal integrity, dual-cavity argon retention, and low-E coating performance. Transit damage covered 14 days from delivery — inspect on receipt before installer signs off.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855200706890,"sku":"TG32-MIDRB-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855200739658,"sku":"TG32-MIDRB-800x600","price":88.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855200772426,"sku":"TG32-MIDRB-1000x800","price":147.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855200805194,"sku":"TG32-MIDRB-1200x1000","price":220.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855200837962,"sku":"TG32-MIDRB-1500x1200","price":330.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_577202a5-a3fe-4659-9e45-6af9d228ea35.webp?v=1779039914"},{"product_id":"made-to-measure-double-glazed-unit-configurator","title":"Made-to-Measure Double Glazed Unit (Configurator)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eAny size, any spec, priced live\u003c\/strong\u003e. A configurable double-glazed sealed unit catalogue entry — the routing flagship for the made-to-measure double-glazing collection. Stock-size variants below are listed as price anchors only; the real path is the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e, where width, height, glass specification, gas fill, coating, and toughening are all combined into a single live-priced quote. £45 minimum, full BS EN 1279 certification, 7-10 working day dispatch on standard rectangular spec.\u003c\/p\u003e\n\n\u003cp\u003eMost replacement-glazing orders don't fit a stock-size grid cleanly. UK casements built between 1965 and 2025 vary in rebate dimensions by mfr, by year, by frame profile, and even by individual sash within a multi-leaf window. Trying to force every project through a 5-size stock list produces a lot of \"close but not quite\" outcomes and frustrating fitter trim-back work. The made-to-measure flagship is the catalogue surface for the configurator's any-size capability — a browseable entry point that lets buyers see real reference prices, then route into the configurator for their actual aperture.\u003c\/p\u003e\n\n\u003ch2\u003eHow this flagship works\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStock-size variants below\u003c\/strong\u003e are listed at the standard argon-double-glazed price per stock size, calculated at £85\/m² × 1.15 argon uplift, £45 floor — the same math the configurator uses. Use these as a sanity check on the configurator's quote for your custom size.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe configurator handles any size from 200×200mm to 3000×2500mm\u003c\/strong\u003e (single-pane manufacturing limit). Below 200×200, units are at the edge of edge-seal yield; above 3000×2500, single-pane manufacturing requires laminated overspec for handling.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThe configurator handles spec stacking\u003c\/strong\u003e — Low-E, toughened, laminated, acoustic-PVB, self-cleaning Activ or Bioclean, custom tints (bronze, grey, body-tinted reflective), and Georgian \/ leaded internal bars.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQuote is delivered live (no email back-and-forth)\u003c\/strong\u003e — the configurator's per-m² + per-spec uplift math is the same math we use internally. The quoted price IS the buy price (no markup at order step).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eTechnical specification (base build)\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eBase overall thickness\u003c\/th\u003e\n\u003ctd\u003e24-28mm (configurable)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandard build-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 16-20mm argon cavity \/ 4mm clear\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon, configurable to krypton (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black (default); steel slim available for conservation spec\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (uncoated argon)\u003c\/th\u003e\n\u003ctd\u003e1.4 W\/m²K — configurable down to 0.7 W\/m²K with triple-pane Krypton\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~80% uncoated, configurable down to 60% for solar-control tints\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279 (parts 1-6), BS EN 673, BS EN 410\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eConfigurable specs\u003c\/th\u003e\n\u003ctd\u003eLow-E, toughened, laminated, acoustic-PVB, self-cleaning, tinted, internal bars (Georgian, leaded, marginal-light), shape (rectangular, arched, raked, circular)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this flagship is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNon-stock aperture sizes\u003c\/strong\u003e — your existing unit measures something like 873×614mm rather than a clean 800×600 or 1000×800. Configurator handles the actual measurement.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpec stacks our other flagships don't dedicate a product to\u003c\/strong\u003e — Low-E plus toughened plus internal Georgian bars, or self-cleaning plus laminated, or acoustic-PVB plus solar-control tint. The configurator combines specs without forcing a flagship-per-permutation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTrade and contractor orders for non-standard projects\u003c\/strong\u003e — extension new-builds, loft conversions, dormer add-ons where every casement has different dimensions. The configurator's per-unit quote replaces tedious email back-and-forth.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservatory side-panel replacement and odd-shape applications\u003c\/strong\u003e — non-rectangular roof slopes, gable-end inset panels, side-panel wedges. Configurator handles the geometry inputs.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBulk-order trade accounts\u003c\/strong\u003e — single configurator session can quote 20+ different unit specs in 15 minutes; faster than per-unit emails to a supplier.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor specific spec flagships with dedicated stock-size variants, see the \u003ca href=\"\/products\/24mm-clear-double-glazed-unit\"\u003e\u003cstrong\u003e24mm Clear Double Glazed Unit (Standard Argon)\u003c\/strong\u003e\u003c\/a\u003e, \u003ca href=\"\/products\/28mm-low-e-a-rated-double-glazed-unit\"\u003e\u003cstrong\u003e28mm Low-E A-Rated Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e, or browse the full \u003ca href=\"\/collections\/double-glazing\"\u003e\u003cstrong\u003edouble glazing collection\u003c\/strong\u003e\u003c\/a\u003e. For triple glazing, the \u003ca href=\"\/collections\/triple-glazing\"\u003etriple glazing collection\u003c\/a\u003e covers the equivalent flagships.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes (reference anchors)\u003c\/h2\u003e\n\u003cp\u003eFive reference-anchor stock sizes are listed below, priced at the standard argon-double-glazed rate. These are listed primarily so buyers can sanity-check the configurator's quote against a known stock price for a near-equivalent size. The real path for actual orders is the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003econfigurator\u003c\/strong\u003e\u003c\/a\u003e — same math, exact aperture dimensions, spec uplift applied transparently.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance, argon-fill certificate (or krypton, depending on spec), warm-edge spacer identification, and Letter of Conformance referencing the configured spec. For commercial or contract work, additional certification (BS EN 12150 toughening stamp, BS EN 14449 laminated certificate, BS EN ISO 9227 salt-spray for coastal coatings) is supplied automatically when those specs are configured.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow is the configurator priced?\u003c\/h3\u003e\n\u003cp\u003ePer-m² base of £85, multiplied by spec uplifts (Low-E 1.25×, toughened 1.15×, triple-pane 1.50×, acoustic-laminated 1.30×, slim-krypton 1.40×), plus flat per-m² uplifts for self-cleaning coatings (£35\/m²). Floor is £45 per unit. The configurator's quote = the buy price; no markup at order step. This is the same math used to set the stock-size variant prices on every Pane Relief flagship product.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the minimum size I can order?\u003c\/h3\u003e\n\u003cp\u003e200×200mm. Below this, edge-seal yield drops sharply and the unit becomes uneconomic. For very small specialist sizes (signal-glazing inserts, mirror-fit small panels), contact us directly for a manufacturing-feasibility check.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the maximum size?\u003c\/h3\u003e\n\u003cp\u003e3000×2500mm in single-pane manufacturing. Above this size, the float-glass plant handling and tempering equipment hits its size cap, and units in this range require oversized handling and freight which we coordinate at order step. For oversize commercial spec, contact the trade desk for a custom quote.\u003c\/p\u003e\n\n\u003ch3\u003eCan I get a quote without ordering?\u003c\/h3\u003e\n\u003cp\u003eYes — the configurator delivers a written quote PDF on completion. Quote is valid for 30 days from generation; pricing locked at the per-m² rate at quote time (we don't surprise-uplift between quote and order).\u003c\/p\u003e\n\n\u003ch3\u003eLead time for configured orders?\u003c\/h3\u003e\n\u003cp\u003e7-10 working days for standard rectangular argon-double spec. Add 3 days for Low-E coating, 3 days for toughening (BS EN 12150), 3-5 days for lamination (BS EN 14449), 5-7 days for shaped (arched, raked, circular), 14-21 days for triple-pane builds, 21-28 days for ultra-slim conservation specs.\u003c\/p\u003e\n\n\u003ch3\u003eCan I configure for a heritage \/ listed-building application?\u003c\/h3\u003e\n\u003cp\u003eYes — the configurator includes slim-cavity, krypton-fill, narrow steel spacer, and reduced-pane-thickness options. For listed-building consent submissions, we recommend the dedicated \u003ca href=\"\/products\/12mm-histoglass-equivalent-slim-conservation-unit\"\u003e12mm Histoglass-Equivalent Slim Conservation Unit\u003c\/a\u003e flagship which carries the conservation-officer documentation flow built in. Alternatively, configure a slim spec in the configurator and request the Listed-Building Compatibility Statement at order step.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty on configured units?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2 accelerated weathering). 10 years on gas retention to ≥80% of initial fill. 10 years on coating performance (Low-E, self-cleaning). Transit damage covered 14 days from delivery. The same warranty applies whether you order a stock-size or a configured bespoke unit.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855200969034,"sku":"DG-MTM-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201001802,"sku":"DG-MTM-800x600","price":47.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855201034570,"sku":"DG-MTM-1000x800","price":79.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855201067338,"sku":"DG-MTM-1200x1000","price":118.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855201100106,"sku":"DG-MTM-1500x1200","price":176.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_0b9a0f52-2d7c-4696-9a59-b9d07906801e.webp?v=1779039916"},{"product_id":"28mm-triple-glazed-slim-rebate-retrofit-unit","title":"28mm Triple Glazed Unit (Slim Rebate Retrofit)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eTriple-glazing performance in a 28mm-rebate frame\u003c\/strong\u003e. A 28mm triple-glazed sealed unit (3mm clear \/ 8mm argon \/ 3mm clear with planitherm soft-coat \/ 8mm argon \/ 3mm clear) gives the thermal envelope of a triple-pane build without forcing a frame swap. The 28mm overall thickness drops straight into the same rebate that originally housed a 28mm double-glazed unit — the most common UK replacement scenario for early-2000s PVCu, aluminium, and timber casements.\u003c\/p\u003e\n\n\u003cp\u003eMost homeowners assume triple glazing requires a 36mm or 44mm rebate (the standard for new-build triple), which means tearing out the frame. The slim-rebate triple build solves that constraint: thinner panes (3mm not 4mm), narrower cavities (8mm not 16-20mm), and argon-not-krypton keeps the price below specialist territory. The trade-off is U-value: ~1.0 W\/m²K centre-pane vs ~0.7 W\/m²K for a full-fat 44mm krypton triple. Still meaningfully better than any 28mm double-glazed unit.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e3mm clear \/ 8mm argon \/ 3mm clear with Planitherm Total+ soft-coat (face 3) \/ 8mm argon \/ 3mm clear with Planitherm Total+ soft-coat (face 5)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon, both cavities (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black — twin spacers\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.0 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (whole window, PVCu frame)\u003c\/th\u003e\n\u003ctd\u003e~1.3 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.50\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~71% (twin Low-E coatings reduce LT vs single-coat)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA (in compliant frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSound reduction (Rw)\u003c\/th\u003e\n\u003ctd\u003e~33 dB (twin cavities give modest acoustic uplift over double)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673 (U-value), BS EN 410 (light\/solar), BS EN 12758 (acoustic)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2002-2015 PVCu casements with 28mm-rebated sashes\u003c\/strong\u003e — the dominant UK replacement-window vintage. The rebate accepts 28mm overall; full-fat triple won't fit without re-rebating or full frame replacement.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAluminium curtain-walling and aluminium casements with 28mm rebates\u003c\/strong\u003e — commercial \/ shop-front retrofits where frame replacement is uneconomic but Building Regs Part L compliance is required.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eListed buildings with conservation-officer-mandated 28mm rebate retention\u003c\/strong\u003e — where the original sash sightline must be preserved and Krypton-slim alternatives don't deliver enough thermal performance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApproved Document L1B replacement compliance\u003c\/strong\u003e where a 28mm Low-E double won't quite hit the target — the triple build buys 0.1-0.2 W\/m²K headroom for borderline cases.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperty re-mortgage \/ EPC upgrade prep\u003c\/strong\u003e — A-rated WER on a 28mm-rebate frame lifts the building's energy band without the disruption of full frame replacement.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor frames rebated for 32mm units, the \u003ca href=\"\/products\/32mm-triple-glazed-mid-thickness-retrofit-unit\"\u003e\u003cstrong\u003e32mm Triple Glazed Mid-Thickness Retrofit\u003c\/strong\u003e\u003c\/a\u003e sits in the middle of the cavity-depth \/ cost \/ U-value tradeoff. For new-build or full frame replacement projects, the \u003ca href=\"\/products\/36mm-standard-triple-glazed-unit\"\u003e\u003cstrong\u003e36mm Standard Triple Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e and \u003ca href=\"\/products\/44mm-premium-triple-glazed-krypton-low-e-unit\"\u003e\u003cstrong\u003e44mm Premium Triple Krypton\u003c\/strong\u003e\u003c\/a\u003e options give better thermals. The full \u003ca href=\"\/pages\/triple-glazing\"\u003e\u003cstrong\u003etriple-glazing topical page\u003c\/strong\u003e\u003c\/a\u003e covers the cavity-depth decision tree.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes are listed below. Custom rectangular sizes and shaped variants are priced via the \u003ca href=\"\/pages\/configure\"\u003e\u003cstrong\u003eonline glass configurator\u003c\/strong\u003e\u003c\/a\u003e. Dispatch is 10-14 working days from order (twin sealed-unit assembly + dual low-E coatings add 3-5 days vs standard double).\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery unit ships with: UKCA mark, BS EN 1279 Declaration of Performance, dual-cavity argon-fill certificate, low-E coating identification on both surfaces, and a Letter of Conformance referencing BS EN 673 (U-value), BS EN 410 (light\/solar), and BS EN 12758 (acoustic). For Approved Document L sign-off, the supplied U-value certificate is sufficient evidence.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWill this really fit a 28mm rebate?\u003c\/h3\u003e\n\u003cp\u003eYes — that's the entire design intent. The overall thickness is 28mm ± 0.5mm (BS EN 1279-1 tolerance). Confirm your existing unit reads 28mm overall with calipers at the rebate after carefully removing the inner bead. If your existing unit is 24mm overall, the rebate may be 24mm — in which case the 28mm slim-rebate triple needs a 4mm rebate deepening (achievable via beading swap in PVCu, harder in aluminium).\u003c\/p\u003e\n\n\u003ch3\u003eWhy not just go full 36mm triple?\u003c\/h3\u003e\n\u003cp\u003eA 36mm triple requires a 36mm rebate. Most pre-2015 UK replacement frames are rebated for 28mm. Retrofitting full-fat triple means tearing out the frame — typically £400-600 per opening for PVCu replacement, plus disruption. The 28mm slim-rebate build buys 80-85% of the thermal performance for 5-10% of the disruption cost.\u003c\/p\u003e\n\n\u003ch3\u003eHow much better than a 28mm Low-E double?\u003c\/h3\u003e\n\u003cp\u003eU-value: 28mm triple = 1.0 W\/m²K centre-pane vs 28mm Low-E double = 1.1 W\/m²K. Marginal on paper, but the triple delivers the third pane's radiant-heat-reflection more reliably across temperature differentials. In a -5°C external \/ +20°C internal test, the triple's internal pane surface temperature is ~17°C vs the double's ~14°C — meaningful for condensation-prone bedrooms and bathrooms.\u003c\/p\u003e\n\n\u003ch3\u003eAcoustic performance?\u003c\/h3\u003e\n\u003cp\u003eRw ~33 dB — modest 3 dB uplift over a 28mm Low-E double (Rw ~30 dB). The twin cavity helps with low-frequency rumble (HGVs, washing machines through walls), but for serious acoustic problems the \u003ca href=\"\/products\/triple-glazed-acoustic-unit-44db-rw\"\u003eTriple Glazed Acoustic Unit (44 dB Rw)\u003c\/a\u003e with PVB interlayer is the right call. See \u003ca href=\"\/pages\/acoustic-glass\"\u003eacoustic glass topical page\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eLead time?\u003c\/h3\u003e\n\u003cp\u003e10-14 working days. The twin sealed-unit assembly adds 3-5 days over a standard double, and the dual low-E coating runs are scheduled in batches by the float-glass coating supplier. Shaped or non-stock sizes add another 5-7 days.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2 accelerated-weathering tested). 10 years on argon retention to ≥80% of initial fill across both cavities. 10 years on low-E coating integrity. Transit damage covered 14 days from delivery.\u003c\/p\u003e\n\n\u003ch3\u003eCan it be specified shaped (arched, raked)?\u003c\/h3\u003e\n\u003cp\u003eYes — see the \u003ca href=\"\/products\/shaped-triple-glazed-unit-arched-raked-circular\"\u003eShaped Triple Glazed Unit (Custom Cut)\u003c\/a\u003e flagship for the bespoke template flow. Shaped triple in a 28mm rebate is uncommon but achievable on simple geometric cuts (arched-top, raked-top); circular and elliptical inserts at 28mm overall are at the edge of manufacturing yield.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855201165642,"sku":"TG28-SLIMRB-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201198410,"sku":"TG28-SLIMRB-800x600","price":88.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855201231178,"sku":"TG28-SLIMRB-1000x800","price":147.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855201263946,"sku":"TG28-SLIMRB-1200x1000","price":220.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855201296714,"sku":"TG28-SLIMRB-1500x1200","price":330.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_ea9c6496-98e7-4ec7-b71f-b022fe747835.webp?v=1779039918"},{"product_id":"11-5mm-ultra-slim-conservation-double-glazed-unit","title":"11.5mm Ultra-Slim Conservation Double Glazed Unit","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eThe thinnest commercially viable sealed unit for the most demanding listed-building consents\u003c\/strong\u003e. An 11.5mm slim double-glazed sealed unit (3mm clear \/ 5.5mm krypton cavity \/ 3mm clear with Planitherm Total+ soft-coat) — the smallest cavity-and-pane combination that still passes BS EN 1279 edge-seal integrity testing. Below this thickness, manufacturing yield collapses and edge-seal warranties become uneconomic. Specified for Grade I and Grade II* listed buildings where 12mm overall is still too visible at the rebate.\u003c\/p\u003e\n\n\u003cp\u003eThe 11.5mm build is the bottom of the slim-cavity-krypton market. Most slim-DG suppliers stop at 12mm because the yield rate drops sharply below that — 3mm panes are at the edge of manufacturing tolerance for laminated edge-seal application, and 5.5mm cavities require tighter spacer-bar precision than standard production. We list this flagship because some Grade I consent processes specifically require sub-12mm overall thickness as a condition of approval. For most listed-building work, the \u003ca href=\"\/products\/12mm-histoglass-equivalent-slim-conservation-unit\"\u003e12mm Histoglass-Equivalent\u003c\/a\u003e is the right call; the 11.5mm exists for the cases that require it.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e11.5mm ± 0.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e3mm clear \/ 5.5mm krypton-filled cavity \/ 3mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% krypton (BS EN 1279-3, tighter fill-precision tolerance)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eUltra-narrow steel spacer, black powder-coated — typically 3-4mm visible at sightline\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e~1.7 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.60\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~78%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSightline match\u003c\/th\u003e\n\u003ctd\u003eSub-12mm — appears single-glazed from street at typical viewing distances\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, Historic England Technical Guidance Note (HETGN) on ultra-slim heritage glazing\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003ePane thickness note\u003c\/th\u003e\n\u003ctd\u003e3mm clear is the edge of UK float-glass spec for sealed-unit production; sourced from Pilkington heritage-glass batch runs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGrade I listed buildings where the conservation-officer consent specifies sub-12mm overall thickness\u003c\/strong\u003e — typically late-Georgian and Regency town houses, country houses, ecclesiastical properties.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGrade II* (Star-listed) properties with strict sightline-preservation conditions\u003c\/strong\u003e — heritage glazing where the 12mm spec was reviewed and rejected as still too visible at the rebate edge.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOriginal crown-glass and cylinder-glass replacement\u003c\/strong\u003e in pre-Victorian sash windows where the original glazing was 2-3mm thick and the rebate is sized to match.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLambs-tongue glazing-bar profile retention\u003c\/strong\u003e in fine Georgian and Federalist sash bars where 12mm overall is too thick for the rebate-shoulder profile.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eScheduled Monument and Grade A (Scotland) listed building consents\u003c\/strong\u003e where the heritage consent process specifies sub-12mm as a hard requirement.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor most listed-building work, the \u003ca href=\"\/products\/12mm-histoglass-equivalent-slim-conservation-unit\"\u003e\u003cstrong\u003e12mm Histoglass-Equivalent Slim Conservation Unit\u003c\/strong\u003e\u003c\/a\u003e is the right call (cheaper, faster lead time, longer warranty). The 11.5mm is for the most demanding consents. For 14mm slim with slightly better thermals and full standard manufacturing yield, see the \u003ca href=\"\/products\/14mm-slim-krypton-conservation-double-glazed-unit\"\u003e\u003cstrong\u003e14mm Slim Krypton Conservation Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e. The \u003ca href=\"\/pages\/slim-double-glazing\"\u003e\u003cstrong\u003eslim double glazing topical page\u003c\/strong\u003e\u003c\/a\u003e walks the spec-tier comparison.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFour small-format stock sizes below — the 11.5mm market is dominated by small-pane Georgian sash bars and narrow Edwardian casements, so we cap at 1200×1000mm. For larger heritage apertures, custom-sized units are priced via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e with manufacturing-yield premiums where the unit area exceeds 1.2m² (yield drops sharply above this size). Dispatch is 21-28 working days (slow due to specialist 3mm float-glass batch scheduling).\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance, krypton-fill certificate (≥85% initial fill, tighter tolerance than standard slim), ultra-narrow steel spacer identification, Planitherm low-E coating face identification, and a Listed-Building Compatibility Statement on request — specifically referencing Historic England HETGN guidance on ultra-slim heritage glazing for Grade I and II* consent submissions. For Scheduled Monument or Grade A consents, additional bespoke documentation can be prepared on request.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWhy not just specify the 12mm equivalent?\u003c\/h3\u003e\n\u003cp\u003eFor most listed-building consents, you should — it's cheaper, has better manufacturing yield, longer effective warranty, and faster lead time. The 11.5mm exists for consents where a conservation officer has specifically reviewed and rejected 12mm as too visible. If your consent reads \"sub-12mm overall thickness\", you need this. If your consent reads \"slim-cavity glazing acceptable\" without a hard millimetre limit, the 12mm equivalent will likely satisfy.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the realistic field lifespan?\u003c\/h3\u003e\n\u003cp\u003e8-12 years before edge-seal degradation likely causes misting on south-facing aspects, vs 12-15 years for the 12mm spec. The 3mm panes flex marginally more under thermal cycling than 4mm panes, and the 5.5mm cavity puts higher stress on the edge seal per cycle. We warrant 10 years on edge-seal integrity but realistic expectation is 10-12 years before signs of seal age appear.\u003c\/p\u003e\n\n\u003ch3\u003eWhy does the spec specify 3mm panes when 4mm is standard?\u003c\/h3\u003e\n\u003cp\u003eTo keep overall thickness sub-12mm while preserving cavity volume for thermal performance. A 4-4-4 build is 12mm overall; a 3-5.5-3 build is 11.5mm with more cavity (5.5mm vs 4mm). The cavity volume is the thermal performance driver, so the trade is: marginally thinner panes for a marginally wider gas-fill gap. The panes are sourced from Pilkington heritage-glass batch runs (manufactured for stained-glass and conservation lead-light work) where 3mm float is a standard product.\u003c\/p\u003e\n\n\u003ch3\u003eU-value vs 12mm Histoglass equivalent?\u003c\/h3\u003e\n\u003cp\u003eCentre-pane U-value: 11.5mm = ~1.7 W\/m²K vs 12mm = ~1.6 W\/m²K. The difference is marginal — within measurement noise on the test rig. Both are roughly 3× better than the single glass they replace (5.7 W\/m²K). For consent compliance the difference is irrelevant; for actual thermal performance you'll feel no perceptible difference between 11.5mm and 12mm in service.\u003c\/p\u003e\n\n\u003ch3\u003eLead time honesty?\u003c\/h3\u003e\n\u003cp\u003e21-28 working days, sometimes longer. The 3mm float-glass batch runs at Pilkington are scheduled monthly; if your order arrives in week 1 of a batch cycle, lead time is faster (closer to 21 working days), if in week 3 then closer to 28. We confirm a tighter lead-time estimate at order acknowledgement.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the cost premium over 12mm?\u003c\/h3\u003e\n\u003cp\u003eRoughly 10-15% over the equivalent 12mm Histoglass-equivalent unit. The premium reflects: lower manufacturing yield (more units rejected at QC), specialist 3mm pane sourcing, and tighter spacer-bar production tolerance. For high-profile listed-building consent work the premium is small relative to project scope; for routine slim-DG retrofits the 12mm is the better economic spec.\u003c\/p\u003e\n\n\u003ch3\u003eAvailable shaped?\u003c\/h3\u003e\n\u003cp\u003eYes, but at significant cost premium and lead-time extension. Shaped 11.5mm units (arched, circular) cost ~2.0-2.5× the rectangular equivalent and lead time stretches to 28-35 working days. For shaped heritage glazing, the 14mm slim spec offers better manufacturing yield with only marginally more visible sightline — generally the right call for shaped over rectangular.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855201362250,"sku":"DG115-ULSL-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201395018,"sku":"DG115-ULSL-800x600","price":72.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855201427786,"sku":"DG115-ULSL-1000x800","price":119.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855201460554,"sku":"DG115-ULSL-1200x1000","price":179.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_4674ab57-f157-46d5-8bc7-d3e8e3985ea7.webp?v=1779039920"},{"product_id":"12mm-histoglass-equivalent-slim-conservation-unit","title":"12mm Histoglass-Equivalent Slim Conservation Unit","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eListed-building-approved sightline with double-glazed thermal performance\u003c\/strong\u003e. A 12mm slim double-glazed sealed unit (4mm clear \/ 4mm krypton cavity \/ 4mm clear with Planitherm Total+ soft-coat) — built to match the appearance and sightline of the original single-glazed unit it replaces, while delivering centre-pane U-value of ~1.6 W\/m²K. The Histoglass-equivalent spec is the standard offering UK conservation officers approve for Grade II and Grade II* listed sash and casement windows.\u003c\/p\u003e\n\n\u003cp\u003eHistoglass is a registered trademark of Cambridge-based Slim-Lite Glass, the original UK slim-cavity-Krypton specialist. The \"Histoglass equivalent\" specification is the industry shorthand for a 12mm sealed unit with a krypton-filled narrow cavity (4mm) and a low-E inner pane, manufactured to match the sightline of a 4mm or 6mm single-glazed pane within ±1mm tolerance. Conservation officers regularly approve this spec because the unit reads as single-glass-equivalent from the street, while the homeowner gets meaningful thermal performance.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e12mm ± 0.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 4mm krypton-filled cavity \/ 4mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% krypton (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eNarrow steel spacer, black powder-coated — reads as a dark hairline at sightline edge\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e~1.6 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.60\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~77%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSightline match\u003c\/th\u003e\n\u003ctd\u003e≤1mm from 4mm single-glazed original — conservation-officer-approved appearance\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, Historic England Technical Guidance Note (HETGN) on slim-cavity glazing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGrade II and Grade II* listed buildings with conservation-officer approval for slim DG retrofit\u003c\/strong\u003e — the standard spec your local authority's conservation officer will likely permit. Confirm in writing before ordering; consent requirements vary by authority.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConservation areas with Article 4 directions restricting window changes\u003c\/strong\u003e — slim DG with sightline-match spec typically clears Article 4 requirements where full-fat double does not.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGeorgian and Victorian sash windows being upgraded thermally without losing the original lambs-tongue glazing-bar profile\u003c\/strong\u003e — the 12mm slim unit drops into rebated bars where 24mm units force bar profile changes.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePeriod casement windows in heritage settings\u003c\/strong\u003e — Edwardian cottage casements, Arts and Crafts ranges, Lutyens and Voysey heritage projects.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProperties where full single-pane replacement is uneconomic but planning constraints rule out 24mm DG\u003c\/strong\u003e — the slim 12mm sits in the gap: better than single, conservation-compliant, half the cost of true Histoglass-branded equivalent.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor even thinner builds where 12mm overall is still too visible at the rebate, the \u003ca href=\"\/products\/11-5mm-ultra-slim-conservation-double-glazed-unit\"\u003e\u003cstrong\u003e11.5mm Ultra-Slim Conservation Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e is the next step down — at the edge of commercial manufacturing yield. For 14mm slim with more cavity volume (slightly better thermals, slightly more visible at sightline), see the \u003ca href=\"\/products\/14mm-slim-krypton-conservation-double-glazed-unit\"\u003e\u003cstrong\u003e14mm Slim Krypton Conservation Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e. The \u003ca href=\"\/pages\/slim-double-glazing\"\u003e\u003cstrong\u003eslim double glazing topical page\u003c\/strong\u003e\u003c\/a\u003e walks the conservation-glazing decision tree in depth.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFour heritage-window-appropriate stock sizes below — the smaller bespoke market for listed-building glazing means we cap at 1200×1000mm; for larger heritage apertures, custom-sized units are priced via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e. Dispatch is 14-21 working days from order (slim-cavity krypton-fill manufacturing is sequential and yield-sensitive). Trade and conservation-architect accounts: tiered pricing on log-in.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance, krypton-fill certificate (BS EN 1279-3 tested at ≥85% initial fill), narrow steel spacer identification, Planitherm low-E coating face identification (face 3), and a Listed-Building Compatibility Statement on request — referencing the Historic England Technical Guidance Note (HETGN) on slim-cavity glazing for sash and casement windows. For conservation-officer submission, we supply a CAD-rendered sightline comparison (original single vs replacement 12mm slim) on request.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eWill my conservation officer actually approve this?\u003c\/h3\u003e\n\u003cp\u003eApproval is case-by-case and authority-by-authority. The 12mm Histoglass-equivalent spec is on the more-permissive end of conservation glazing — most authorities permit it where 24mm DG would be refused, on the basis that the sightline match preserves the original window appearance. We supply a Listed-Building Compatibility Statement with each order for conservation-officer submission. Get the consent in writing before ordering; conservation-officer rules vary widely between Westminster, Cambridge, Bath, and rural authorities.\u003c\/p\u003e\n\n\u003ch3\u003eHow is this different from genuine branded Histoglass?\u003c\/h3\u003e\n\u003cp\u003eGenuine Histoglass (Slim-Lite Glass, Cambridge) is the trademark-protected original — manufactured to a specific specification with documented production records used in many high-profile listed-building consents. Our 12mm Histoglass-equivalent uses the same build-up (4-4-4 krypton + low-E) and meets the same sightline tolerance, manufactured to BS EN 1279, but cannot use the Histoglass brand name. Performance is equivalent; the brand is the difference. For projects where the consent specifies \"Histoglass or equivalent\", our spec satisfies the \"equivalent\" clause.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's the lifespan of slim-cavity krypton?\u003c\/h3\u003e\n\u003cp\u003e10-15 years before edge-seal degradation, vs 15-25 years for standard double glazing. The narrower cavity puts more thermal cycling stress on the edge seal, and krypton's higher molecular weight (vs argon) means slower fill loss but tighter seal-integrity tolerances. We warrant 10 years on edge-seal integrity; realistic field life is 12-15 years before misting becomes likely on south-facing aspects.\u003c\/p\u003e\n\n\u003ch3\u003eU-value vs full-fat double glazing — what am I giving up?\u003c\/h3\u003e\n\u003cp\u003eCentre-pane U-value: 12mm slim krypton = ~1.6 W\/m²K vs 28mm Low-E argon double = 1.1 W\/m²K. The slim unit is ~45% worse on paper. In practice, the slim unit is still ~3× better than the original single-glazed pane (single = 5.7 W\/m²K). For heritage applications, the conservation-officer-compliance constraint trumps the thermal-optimisation argument — you can't fit 28mm in the original rebate without losing the listed-building consent.\u003c\/p\u003e\n\n\u003ch3\u003eWill I see the spacer at the edge?\u003c\/h3\u003e\n\u003cp\u003eThe narrow black powder-coated steel spacer reads as a dark hairline at the rebate edge — typically 4-6mm wide visible from inside, less from outside (the original putty or beading covers most of it). Most homeowners find this acceptable; some conservation officers require black aluminium foil tape over the spacer to further reduce visual signature.\u003c\/p\u003e\n\n\u003ch3\u003eCan I get this in shaped (arched, raked) for Gothic-revival windows?\u003c\/h3\u003e\n\u003cp\u003eYes — at the edge of manufacturing yield. Arched and raked slim-cavity krypton units cost roughly 1.8-2.0× the equivalent rectangular unit, with lead times of 21-28 working days. Send a physical cardboard template or accurate CAD for shape-cut.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty in field service?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2 accelerated weathering). 10 years on krypton retention to ≥80% of initial fill. 10 years on Planitherm low-E coating performance. Transit damage covered 14 days from delivery — slim units are more fragile than full-fat double; brief the installer on handling protocol before delivery.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855201558858,"sku":"DG12-HISTG-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201591626,"sku":"DG12-HISTG-800x600","price":72.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855201624394,"sku":"DG12-HISTG-1000x800","price":119.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855201657162,"sku":"DG12-HISTG-1200x1000","price":179.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_357d77ad-d9a2-4fea-8b23-ce53a15bed34.webp?v=1779039922"},{"product_id":"pilkington-activ-self-cleaning-double-glazed-unit","title":"Pilkington Activ Self-Cleaning Double Glazed Unit (28mm)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eSelf-cleaning by the chemistry of UV + rain\u003c\/strong\u003e. A 28mm double-glazed sealed unit with a Pilkington Activ self-cleaning outer pane and a Planitherm Total+ Low-E inner pane, argon-filled, delivering A-rated thermal performance while dramatically reducing the frequency of external glass cleaning. Pilkington Activ is the original self-cleaning glass — launched in 2002, now the dominant UK self-cleaning specification on residential and commercial new-build.\u003c\/p\u003e\n\n\u003cp\u003eThe self-cleaning mechanism is two-stage: photocatalytic + hydrophilic. The outer pane carries a microscopically thin titanium-dioxide (TiO₂) coating that, when exposed to UV from daylight, breaks down organic dirt (bird droppings, leaf residue, atmospheric grease, algae spores) via a photocatalytic redox reaction. When it rains, the TiO₂ surface becomes hydrophilic — water spreads as a sheeting film rather than beading into droplets — and the loosened dirt is rinsed away with the sheeting flow, leaving a streak-free finish without mineral spots.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e28mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm Pilkington Activ outer (TiO₂ coating face 1) \/ 20mm argon cavity \/ 4mm clear with Planitherm Total+ soft-coat (face 3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOuter coating\u003c\/th\u003e\n\u003ctd\u003ePilkington Activ — pyrolytic titanium dioxide, applied on float-line during glass manufacture (permanent, cannot wear off)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e1.1 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.61\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~77%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA (in compliant frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSelf-cleaning activation\u003c\/th\u003e\n\u003ctd\u003eUV-A daylight (works even on overcast UK winter days; faster cycle on bright south-facing aspects)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279, BS EN 673, BS EN 410, Pilkington Activ datasheet (Pilkington publication 8005)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere this unit is the right call\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHard-to-clean window locations\u003c\/strong\u003e — first-floor and upper-storey externals, dormer windows, conservatory roof panels, gable-end and apex glazing, atrium glazing, and any window where access for cleaning is awkward or costly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBird-droppings prone aspects\u003c\/strong\u003e — windows beneath tree canopies, near garden features that attract birds, coastal aspects with gull activity. The photocatalytic effect breaks down the organic guano faster than it can stain.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePollen and tree-sap exposed locations\u003c\/strong\u003e — sycamore, lime, and oak tree drip-zone glazing where standard glass becomes spotted within weeks.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCommercial and rental property where cleaning costs are recurring\u003c\/strong\u003e — letting agents and facilities managers find the maintenance cost reduction justifies the spec uplift within 3-5 years.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eA-rated WER + self-cleaning in one spec\u003c\/strong\u003e — Building Regs L compliance plus low maintenance, the standard residential new-build self-cleaning brief.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor coastal aspects where salt film is the dominant cleaning issue, the \u003ca href=\"\/products\/saint-gobain-bioclean-self-cleaning-coastal-unit\"\u003e\u003cstrong\u003eSaint-Gobain Bioclean Self-Cleaning Coastal Unit\u003c\/strong\u003e\u003c\/a\u003e has better salt-rinse performance in field testing. For the dedicated self-cleaning topical context, see the \u003ca href=\"\/pages\/self-cleaning-glass\"\u003e\u003cstrong\u003eself-cleaning glass topical page\u003c\/strong\u003e\u003c\/a\u003e. For standard non-coated A-rated, the \u003ca href=\"\/products\/28mm-low-e-a-rated-double-glazed-unit\"\u003e\u003cstrong\u003e28mm Low-E A-Rated Double Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e is the cheaper alternative.\u003c\/p\u003e\n\n\u003ch2\u003eStock sizes and pricing\u003c\/h2\u003e\n\u003cp\u003eFive UK-standard stock sizes below. Dispatch 7-10 working days from order. The Pilkington Activ outer pane adds £35\/m² flat over the equivalent uncoated Low-E build — the configurator routes custom sizes via the same per-m² rate. Trade accounts: tiered volume pricing on log-in.\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eUKCA mark, BS EN 1279 Declaration of Performance, Pilkington Activ outer-pane authentication certificate (sealed unit identifies coated pane orientation), argon-fill certificate, Planitherm low-E coating identification, and a Letter of Conformance referencing the Pilkington Activ technical datasheet for the self-cleaning performance claim. For commercial spec-sheets, we supply the full Pilkington Activ life-cycle assessment on request.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eDoes it actually clean itself, or do I still need to wash it?\u003c\/h3\u003e\n\u003cp\u003eIt cleans itself of organic dirt (bird droppings, leaf residue, pollen, atmospheric grease, algae spores) and rinses to streak-free with rainfall. It does not remove paint splatter, builder's-grade silicone smears, or mineral spots from hard-water borehole spray — those need manual cleaning. The realistic claim: 80-90% reduction in cleaning frequency, not 100% elimination.\u003c\/p\u003e\n\n\u003ch3\u003eDoes it work in shade or in winter?\u003c\/h3\u003e\n\u003cp\u003eThe photocatalytic reaction needs UV-A, which is present even on overcast UK winter days at 5-15% of summer levels. North-facing windows in deep shade still receive enough UV to maintain the cycle, just slower (a north-facing dirt cycle that resets in a week south-facing might take 2-3 weeks north-facing). For sustained efficacy, daylight (not direct sunlight) is sufficient.\u003c\/p\u003e\n\n\u003ch3\u003eWill the coating wear off over time?\u003c\/h3\u003e\n\u003cp\u003eNo. Pilkington Activ is a pyrolytic coating, applied at the float-glass production stage at ~600°C — the titanium dioxide is fused into the glass surface molecular structure. It cannot be wiped off, scratched off, or weathered off. The performance claim is for the lifetime of the glass.\u003c\/p\u003e\n\n\u003ch3\u003eCan I use cleaning products on it?\u003c\/h3\u003e\n\u003cp\u003eYes, but you usually don't need to. If you do wash externally, use clear water with a soft sponge — no detergent, no vinegar, no abrasive cloth. Glass-cleaning fluids deposit residues that interrupt the photocatalytic cycle until the next rain. Avoid silicone-based glass treatments (Rain-X and similar) — they coat over the Activ layer and block the photocatalytic mechanism.\u003c\/p\u003e\n\n\u003ch3\u003eHow does it compare to Saint-Gobain Bioclean?\u003c\/h3\u003e\n\u003cp\u003eActiv and Bioclean are both pyrolytic TiO₂ self-cleaning coatings with very similar performance specs. Activ is the original (Pilkington, launched 2002) and dominates the UK residential market. Bioclean (Saint-Gobain, launched 2003) has marginally better field-test performance in coastal salt-film conditions. For inland aspects, either works; for coastal, prefer Bioclean. See the \u003ca href=\"\/products\/saint-gobain-bioclean-self-cleaning-coastal-unit\"\u003eBioclean Coastal flagship\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eLead time and warranty?\u003c\/h3\u003e\n\u003cp\u003e7-10 working days dispatch. 10-year warranty on edge-seal integrity, argon retention, and Low-E inner-pane performance. The Pilkington Activ outer coating is covered by Pilkington's own 10-year performance warranty (passed through to end-user via our supply chain).\u003c\/p\u003e\n\n\u003ch3\u003eDoes it work on conservatory roofs?\u003c\/h3\u003e\n\u003cp\u003eYes — and arguably this is where self-cleaning glass earns its keep most. Conservatory roof panels are nearly impossible to clean from below and dangerous to clean from above. Activ keeps the panels clear of organic deposits without ladder access. For conservatory-specific specifications, the configurator includes a \"conservatory roof glazing\" option that lifts the toughened-outer requirement (BS EN 12150) automatically.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855201755466,"sku":"DG28-ACTIV-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201788234,"sku":"DG28-ACTIV-800x600","price":76.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855201821002,"sku":"DG28-ACTIV-1000x800","price":126.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855201853770,"sku":"DG28-ACTIV-1200x1000","price":189.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855201886538,"sku":"DG28-ACTIV-1500x1200","price":283.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/double-glazed-sealed-unit-igu-product-cutaway_138a8998-d836-4ed3-865a-d0557853c487.webp?v=1779039924"},{"product_id":"shaped-triple-glazed-unit-arched-raked-circular","title":"Shaped Triple Glazed Unit (Custom Cut — Arched \/ Raked \/ Circular)","description":"\n\u003cp class=\"pr-flagship__lede\"\u003e\u003cstrong\u003eTriple glazing for the non-rectangular aperture\u003c\/strong\u003e. Shaped sealed units — arched-top windows, raked-top apex casements, circular portholes, elliptical bullseyes, Gothic-point ecclesiastical glazing, sliver and wedge cuts for gable apex insets — are cut to owner-supplied template or measured site survey. The 36mm triple-glazed build delivers full A-rated WER performance in geometries that standard stock units cannot serve.\u003c\/p\u003e\n\n\u003cp\u003eMost shaped-glazing demand sits in three buckets: heritage \/ period homes with original arched or Gothic-point sashes; modernist architectural casements where the apex of a gable or the curve of a cantilever is fully glazed; and conservatories \/ orangeries where roof-tile alignment forces non-rectangular side panels. This flagship handles all three via the same template-driven cut workflow.\u003c\/p\u003e\n\n\u003ch2\u003eTechnical specification (base 36mm triple build)\u003c\/h2\u003e\n\u003ctable class=\"pr-spec-table\"\u003e\n  \u003ctr\u003e\n\u003cth\u003eOverall thickness\u003c\/th\u003e\n\u003ctd\u003e36mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBuild-up\u003c\/th\u003e\n\u003ctd\u003e4mm clear \/ 12mm argon \/ 4mm clear with Planitherm Total+ soft-coat (face 3) \/ 12mm argon \/ 4mm clear\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eGas fill\u003c\/th\u003e\n\u003ctd\u003e90% argon (BS EN 1279-3)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSpacer bar\u003c\/th\u003e\n\u003ctd\u003eWarm-edge composite, black — twin spacers contoured to shape\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eU-value (centre-pane)\u003c\/th\u003e\n\u003ctd\u003e0.8 W\/m²K\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eg-value\u003c\/th\u003e\n\u003ctd\u003e0.50\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eLight transmittance\u003c\/th\u003e\n\u003ctd\u003e~71%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBFRC Window Energy Rating\u003c\/th\u003e\n\u003ctd\u003eA or A+ (depending on frame, area, ratio)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStandards\u003c\/th\u003e\n\u003ctd\u003eBS EN 1279 (parts 1-6), BS EN 673, BS EN 410\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eShape capability\u003c\/th\u003e\n\u003ctd\u003eArched-top, raked-top, circular, elliptical, Gothic-point, trapezoid, wedge, bespoke per template\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eShape categories we cut\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eArched-top (Roman arch, segmental arch, semi-circular)\u003c\/strong\u003e — period property top-light windows, Georgian and Victorian arched casements. Template: bottom dimensions + arch radius \/ springing height.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRaked-top (sloped-top apex casement, gable inset)\u003c\/strong\u003e — modern architectural glazing on gable ends, dormer cheek casements. Template: 3-corner dimensions + apex angle.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCircular and elliptical (bullseye, porthole, oval)\u003c\/strong\u003e — period villa portholes, contemporary feature glazing. Template: diameter (circle) or major\/minor axes (ellipse).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGothic-point (lancet, pointed-arch)\u003c\/strong\u003e — ecclesiastical and church-conversion glazing, neo-Gothic period houses. Template: base width + apex height + point angle.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTrapezoid and wedge cuts\u003c\/strong\u003e — gable apex slivers, stair-half-landing tall glazing, infill panels in skylight runs.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompound shapes (arch + base rectangle, arch + raked, bespoke)\u003c\/strong\u003e — fully bespoke per CAD or scanned template.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eSquare or rectangular triple glazing is faster and cheaper — see the \u003ca href=\"\/products\/36mm-standard-triple-glazed-unit\"\u003e\u003cstrong\u003e36mm Standard Triple Glazed Unit\u003c\/strong\u003e\u003c\/a\u003e for stock-size rectangular triple. For shaped doubles (less expensive, less thermal performance), see the \u003ca href=\"\/pages\/double-glazing\"\u003e\u003cstrong\u003edouble-glazing topical page\u003c\/strong\u003e\u003c\/a\u003e. For shaped acoustic or safety triple, configure via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e after selecting the shape category.\u003c\/p\u003e\n\n\u003ch2\u003eTemplate requirements\u003c\/h2\u003e\n\u003cp\u003eFor shaped triple, we need a template — either a physical cardboard \/ hardboard template at 1:1 scale, or a CAD file (DWG \/ DXF \/ SVG \/ PDF with measured dimensions), or photographs with reference measurements (tape measure visible at the four cardinal points). Templates are bonded to the cutting glass during production, so accuracy at template stage = accuracy at delivery stage.\u003c\/p\u003e\n\n\u003cp\u003eFor circular and elliptical units, a measured radius \/ major-axis \/ minor-axis sometimes suffices without template, provided the aperture is true (not slightly squashed from frame movement). For all other shapes, send a template — the configurator includes upload paths for CAD and photo.\u003c\/p\u003e\n\n\u003ch2\u003eStock pricing — rectangular reference only\u003c\/h2\u003e\n\u003cp\u003eThe \"stock sizes\" below are notional reference points for cost expectation; the actual shaped unit price is per-shape per-template, quoted within 24 hours of template receipt. Use these as a comparison anchor: a shaped triple costs roughly 1.3-1.6× the equivalent-area rectangular triple, depending on cut complexity (arched: 1.3×; raked: 1.4×; circular: 1.5×; bespoke: 1.6×).\u003c\/p\u003e\n\n\u003ch2\u003eCertification and standards\u003c\/h2\u003e\n\u003cp\u003eEvery shaped unit ships with: UKCA mark, BS EN 1279 Declaration of Performance, argon-fill certificate, shape-specific manufacturing record (template ID + cut tolerances ± 1.5mm), and BFRC WER calculation where the shape is large enough to register against the calculation methodology. For listed-building consents, we provide a heritage-glazing compatibility statement on request.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eHow accurate are shaped cuts?\u003c\/h3\u003e\n\u003cp\u003eTolerance is ±1.5mm on linear dimensions, ±1.0° on angles, ±0.5mm on radius for circular and elliptical. Within those tolerances, the unit drops into a properly-templated rebate. The most common fitting failure is template error, not manufacturing error — get the template right and the cut is right.\u003c\/p\u003e\n\n\u003ch3\u003eLead time for shaped triple?\u003c\/h3\u003e\n\u003cp\u003e14-21 working days from template approval. Arched and raked add 4-7 days over rectangular triple; circular and elliptical add 7-10 days; compound shapes add 10-14 days. Template approval is sometimes a 2-3 day back-and-forth if measurements need refining — order earlier rather than later for project deadlines.\u003c\/p\u003e\n\n\u003ch3\u003eCan I get shaped acoustic or safety triple?\u003c\/h3\u003e\n\u003cp\u003eYes — both are configurable via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e. Shaped acoustic triple (with PVB interlayer in the middle pane) is straightforward; shaped safety triple (toughened outer \/ laminated middle) needs the safety-glass stack to be cut, toughened, and assembled before lamination — adds 5-7 days lead time.\u003c\/p\u003e\n\n\u003ch3\u003eHeritage \/ listed-building compatibility?\u003c\/h3\u003e\n\u003cp\u003eFor listed buildings, conservation officers typically permit shaped triple glazing where: (a) the sightline matches the original single-glazed unit; (b) the spacer bar is dark \/ recessed so it doesn't read as a modern cavity; (c) the unit is set inside the original rebate without external evidence of the modern build. We provide a heritage-glazing statement on request. For the slimmest heritage build, see the \u003ca href=\"\/products\/12mm-histoglass-equivalent-slim-conservation-unit\"\u003e12mm Histoglass-Equivalent Slim Conservation Unit\u003c\/a\u003e — slim double glazing reads as single-glass-equivalent in most listed-building consents.\u003c\/p\u003e\n\n\u003ch3\u003eWhat if my measurements are slightly wrong?\u003c\/h3\u003e\n\u003cp\u003eTemplates that arrive with measurement errors are flagged before cut — we send back a \"measurement query\" with annotated photos asking for the dimensions in question. Cut-with-error-as-supplied units are not warranted against fit issues. Sending a physical cardboard template is the safest measurement method for tricky shapes; CAD is faster but requires good source data.\u003c\/p\u003e\n\n\u003ch3\u003eWill shaped triple fit in a 28mm-rebated frame?\u003c\/h3\u003e\n\u003cp\u003eNot directly — the base build here is 36mm. For 28mm-rebate frames, configure via the \u003ca href=\"\/pages\/configure\"\u003econfigurator\u003c\/a\u003e with the 28mm slim-rebate triple stack on a shaped template. The slim-rebate shaped triple is at the edge of manufacturing yield (thin panes + shape + dual cavity = more rejected units), so price is roughly 1.8-2.0× the rectangular slim-rebate triple.\u003c\/p\u003e\n\n\u003ch3\u003eWarranty on shaped units?\u003c\/h3\u003e\n\u003cp\u003e10 years on edge-seal integrity (BS EN 1279-2). 10 years on argon retention to ≥80% of initial fill. 10 years on low-E coating performance. Transit damage covered 14 days from delivery — shaped units need particularly careful handling at install, so brief the fitter on receipt protocol before delivery date.\u003c\/p\u003e\n","brand":"Pane Relief","offers":[{"title":"600 × 400 mm","offer_id":61855201952074,"sku":"TG-SHAPED-600x400","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"800 × 600 mm","offer_id":61855201984842,"sku":"TG-SHAPED-800x600","price":71.0,"currency_code":"GBP","in_stock":true},{"title":"1000 × 800 mm","offer_id":61855202017610,"sku":"TG-SHAPED-1000x800","price":118.0,"currency_code":"GBP","in_stock":true},{"title":"1200 × 1000 mm","offer_id":61855202050378,"sku":"TG-SHAPED-1200x1000","price":176.0,"currency_code":"GBP","in_stock":true},{"title":"1500 × 1200 mm","offer_id":61855202083146,"sku":"TG-SHAPED-1500x1200","price":264.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/3515\/2458\/files\/triple-glazed-insulated-glass-unit-igu-cutaway_b2a337b0-c696-4e39-9a44-265db774ab72.webp?v=1779039926"}],"url":"https:\/\/panerelief.co.uk\/collections\/window-glass.oembed","provider":"Pane Relief","version":"1.0","type":"link"}