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uPVC Windows

Replacement sealed units for uPVC window frames. uPVC is the most common frame type in UK homes — and the easiest to reglaze. We supply exact-size sealed units in every thickness from 20mm to 36mm, designed to clip straight into standard uPVC bead systems. Measure, order, fit — no frame modification needed.
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5–7 Day Dispatch
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uPVC frames from any manufacturer — Eurocell, Rehau, Veka, Liniar, Deceuninck, Profile 22 — all accept standard sealed unit thicknesses. Here's how to specify the right unit.

Expert Glazing, Done Right

We're not a national call centre. We're local glaziers who take pride in every job.

Standard Rebate Depths

Most uPVC frames accept 24mm or 28mm units as standard. Newer systems (post-2010) typically take 28mm or 32mm. Older systems (pre-2000) may be 20mm or 24mm. Check the rebate depth before ordering — we supply all thicknesses.

Clip-In Bead System

uPVC frames use internal clip-in glazing beads — a quick, simple reglazing method. Remove beads, lift out old unit, clean the frame, set packers, drop in new unit, snap beads back in. 15-25 minutes per window for an experienced fitter.

Upgrade the Specification

Most uPVC windows installed before 2010 have basic clear glass with air fill. The frame can take a much better unit — Low-E + argon drops the U-value from ~2.8 to ~1.1 W/m²K with no frame changes.

5–7 Day Dispatch

Standard rectangular uPVC units are our highest-volume product. Standard double-glazed units dispatch in 5–7 working days, made to any size. Triple, toughened or laminated units within 10–14 working days.

10-Year Warranty

Every unit carries our 10-year warranty against seal failure and gas retention loss — regardless of the frame manufacturer.

uPVC is the most forgiving frame type for reglazing, but accurate measurement is still essential. Watch for these common issues.

Signs Your Double Glazing Needs Attention

Catching problems early saves money and prevents bigger issues. Here are the telltale signs your windows need professional attention.

Misting Between Panes

Visible fogging or condensation inside the sealed cavity (not on the room-side surface) means the edge seal has failed and moisture has entered. The argon gas is also gone — the unit's U-value has dropped from 1.4 to ~2.8 W/m²K. Replace, don't repair.

Cold Drafts Near Windows

Cold zones near a closed window usually mean a failed perimeter seal between glass and frame, or a degraded gasket. Easy to fix on most frames without replacing the glass — but worth a survey to confirm it's not also an IGU failure.

Sudden Spike in Heating Bills

If your bill jumped without weather or tariff changes, check whether sealed units have failed. A single misted unit on a 4-bed home typically adds £100-200/year to heating cost via lost insulation.

Visible Cracks or Chips

Even hairline edge cracks let moisture in and trigger seal failure within months. Cracks in safety-glazing locations (low-level, doors, bathrooms) are a Building Regs Document N compliance issue — replace promptly with BS EN 12150 toughened equivalent.

Heavy Room-Side Condensation

Streams of water on the inside of the glass on cold mornings usually mean the room-side glass surface is too cold (poor U-value glazing) combined with high indoor humidity. A-rated low-E units (U=1.1) typically eliminate this; the condensation calculator identifies the cause.

Sticky or Misaligned Sashes

Sashes that catch, jam, or won't lock are usually hinges, friction stays, or sash weights that have worn — often fixable without replacing the glass. But check the frame for rot or PVCu reinforcement failure while diagnosing; bad frames need replacement before glass.

⚠️ Noticed any of these issues? Do not wait - small problems become expensive repairs. Get a free assessment today.

Expert Knowledge

uPVC Reglazing: The Complete Trade Guide

Why uPVC Is the Easiest Reglaze

uPVC frames use a clip-in bead system that makes sealed unit replacement straightforward. No putty, no pinning, no drying time. Remove the beads with a stiff putty knife or dedicated bead removal tool, lift out the old unit, clean the rebate, set toe-and-heel packers, place the new unit, and snap the beads back in. An experienced fitter completes a standard window in 15-25 minutes.

Common Unit Thicknesses for uPVC

20mm (4-12-4) — Older uPVC systems, typically pre-1995. Slim rebate frames. Still widely encountered in social housing and older installations.
24mm (4-16-4) — The most common domestic configuration. Fits virtually all standard uPVC frames from 1995 onward.
28mm (4-20-4) — Increasingly standard in newer frame systems. Better acoustic and thermal performance due to wider cavity.
32mm — Triple glazed units or enhanced double glazed with thick panes. Requires a deeper rebate — check before ordering.
36mm — Premium triple glazed specifications. Only fits deep-rebate commercial or modern high-performance uPVC systems.

Upgrading Old uPVC Glass

The single biggest opportunity in uPVC reglazing is specification upgrading. Most uPVC windows installed before 2010 contain basic clear glass with air fill — a U-value of approximately 2.8 W/m²K. The frame itself can accept a much better unit:

Low-E softcoat + argon fill in the same 24mm thickness delivers 1.1 W/m²K — a 61% reduction in heat loss with zero frame modification. The customer gets warmer rooms, lower energy bills, and reduced condensation. Your cost difference per unit is modest; the customer's benefit is dramatic.

Gasket and Packer Replacement

While the glass is out, inspect the glazing gaskets (rubber seals that sit between the glass and frame). Degraded gaskets cause rattling, draughts, and water ingress. Replace them — they're cheap and easy to fit while the beads are off. Toe-and-heel packers should also be checked and replaced if crushed or missing. Proper packing ensures the unit weight is distributed correctly and the window operates smoothly.

Start at the longest bead (usually the side) and work from the middle, not the corner. A stiff 1-inch putty knife angled at 30 degrees pops the bead out of the clip channel without cracking. Mark each bead position (top, bottom, left, right) — they're not always interchangeable. Damaged beads are available from most uPVC stockholders, but it's better not to break them in the first place.

The simplest ordering process in the trade. Measure, order, fit.

How Our Service Works

From first contact to finished job, we make the whole process straightforward and stress-free.

Measure the Rebate

Remove one bead to access the rebate. Measure width, height, and rebate depth to the nearest millimetre. Note glass type if visible (clear, Low-E, tinted, obscure).

Choose Your Specification

Like-for-like or upgrade? We'll quote both. Low-E + argon is the most popular upgrade — same thickness, dramatically better performance. Takes 5 minutes to quote.

Place the Order

Online, by email or by phone. Confirmation and pricing within 24 hours. Trade discounts from 5 units. Volume discounts available.

Fit and Invoice

Standard sizes dispatched in 5–7 working days. You fit in 15-25 minutes per window. Invoice your customer. Job done.
Every configuration available — from basic replacements to premium upgrades. All manufactured to your exact measurements.

What We Can Help With

From quick repairs to complete replacements, we handle all residential and commercial glazing needs.

Standard Clear Replacement

Like-for-like clear glass units in 20mm, 24mm, 28mm, and 32mm. The budget option for customers who want clear glass at minimum cost.

Low-E + Argon Upgrade

Energy-efficient sealed units with softcoat Low-E and argon gas fill. U-values from 1.1 W/m²K. Same thickness as the original — fits straight in.

Triple Glazed Units

For frames with deeper rebates (32mm+). U-values from 0.6 W/m²K. Premium thermal performance without frame replacement.

Acoustic Units

Asymmetric laminated configurations for noise reduction. Ideal for bedrooms and living rooms facing roads. Available in all standard uPVC thicknesses.

Obscure & Privacy

Replacement obscure glass for bathrooms and privacy windows. All standard patterns. Low-E coating available on obscure glass too.

Safety Glass

Toughened or laminated to BS EN 12600 for low-level glazing, doors, and windows adjacent to doors. All uPVC thicknesses available.

Not sure what you need? No problem - we will assess and advise. No obligation, no pressure.

Trusted by Tradespeople & Homeowners

What Our Customers Say

4.4 ★ from 39 Google reviews

  • 25+

    Years in Business

  • 10,000+

    Sealed Units Supplied

  • 39

    Google reviews

  • ★★★★★
    I initially contact Pane Relief to quote for replacing my doors & windows and a conservatory conversion. The quote Ollie gave was comprehensive and honest (I’d had several far higher quotes with “70’s” tactics of stating an exorbitant fee, making a fake call to ‘head office’, then offering a 70% reduction ‘just for me’ - it was a relief not to have to sit through t...

    Sarah Langmead

  • ★★★★★
    I found Ollie online having seen his vans around town. He and his young team have been to the house a few times to remedy issues with old double glazing units and also installed a velux style roof window in our bathroom................ I gotta say, they are very busy and one should try and book in advance, but well worth the wait imo. Great work ethic, a can do att...

    Jolyon Maud

  • ★★★★★
    Ollie and his team have done a lovely job on our home. Totally transformed the place and helped our vision come true! Would totally recommend. Thanks again

    Ashley

Common questions about replacing sealed units in uPVC window frames.

Frequently Asked Questions

Answers to the questions we're asked most.

  • Remove one bead and measure the rebate depth. Most uPVC frames accept 24mm or 28mm units. Older frames (pre-1995) may be 20mm. Newer high-performance frames take 32mm+. If in doubt, measure and tell us — we'll confirm compatibility.

  • Only if the rebate is deep enough (typically 32mm+). Most standard uPVC frames are designed for double glazed units. Check the rebate depth before specifying triple. If it's too shallow, a premium double glazed unit (Low-E + argon + warm-edge) delivers excellent performance within the existing rebate.

  • We recommend it. While the beads are off, inspect the glazing gaskets. Degraded gaskets cause rattling, draughts, and water ingress. Replacement gaskets cost very little and fit in seconds — it's false economy to put new glass on old gaskets.

  • Always check and replace if crushed or missing. Proper packing distributes the unit weight correctly and ensures the window opens/closes smoothly. Bridge and support packers at the correct positions prevent glass contact with the frame.

  • Yes — we supply Low-E + argon units in 20mm (4-12-4) configuration. The narrower cavity means slightly lower thermal performance than 24mm, but it's still a significant upgrade from clear glass. U-value approximately 1.3 W/m²K vs 2.8 for clear.

  • Same process — remove beads, swap the unit. The key difference: tilt-and-turn windows are heavier and the packers are critical for correct operation. Follow the manufacturer's packing diagram (usually stamped on the frame or available from the system supplier).

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Replacement units for fogged double glazing in uPVC frames.
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Triple Glazing

Premium triple glazed units for deep-rebate uPVC systems.
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Order uPVC Replacement Units

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