FENSA-registered glazing experts. Made-to-measure sealed units, shipped UK-wide, backed by a 10-year warranty.
Acoustic glass — Rw up to 44 dB, railway / flight-path / A-road territory
If you can hear individual cars from inside your front room, you've got a glazing problem — not a wall problem. Standard 4-16-4 double glazing achieves around 30 dB Rw; that's enough for a quiet suburban street but nothing more. Add asymmetric panes, a wider cavity, and an acoustic-PVB laminated inner pane, and the same window can hit 38 dB, 42 dB, or 44 dB — taking a busy A-road from intrusive conversation-blocker to background hum. Pane Relief manufactures the full acoustic range — laminated acoustic-PVB sealed units, asymmetric double-glazed builds, and triple-glazed acoustic stacks — to BS EN 12758 and BS EN ISO 10140 lab-measured Rw values. Tell us your noise source (traffic, train, plane, plant) and we'll spec the right curve for the frequency.
You can't sleep through the noise
Flight path, freight line, motorway, late-night main road, neighbour's plant equipment. We've spec'd acoustic units for every flavour of noise problem in the UK. Free UK delivery, 10-year edge-seal warranty, and a phone helpline (08:00-18:00 Mon-Fri) for a free dB-target conversation before you order.
Configure acoustic unitArchitect, M&E, planning condition
BS 8233 dwelling internal-noise targets, planning-condition acoustic specs (typical: 35 dB Rw glazing for residential near A-roads, 38-42 dB Rw near rail and flight paths), schools, hotels, healthcare. Lab-measured Rw + spectrum-adapted C/Ctr values on every build, BS EN 12758 documentation, scheduled site delivery.
Trade & specifier pricingMatch the dB target to the build
Rw values are lab-measured for the glass alone. Real-world site performance loses 2-4 dB to frame leakage and trickle vents. Aim 4 dB above your target.
38 dB Rw — entry-point
Asymmetric 6-16-4 DG with standard PVB inner. The default upgrade from standard 30 dB stock DG. Most domestic noise.
40 dB Rw — A-road
Asymmetric 6.4-20-4 with acoustic-PVB laminated outer. Direct exposure to a busy through-road.
42 dB Rw — rail / dual
10.8-20-4 with thicker acoustic-PVB. Mainline rail, motorway frontage, dual-carriageway.
44 dB+ Rw — flight path
Triple-glazed acoustic stack with two acoustic-PVB layers. Heathrow / Gatwick approach, freight depot perimeter.
Single-pane acoustic
Monolithic acoustic-PVB laminated for secondary glazing, single-glazed sash conservation, partition systems.
Custom spec
Bring your planning-condition spec, target Rw, or noise survey — we'll quote a build that hits the number.
The acoustic dB-reduction math (in plain English)
Decibels are logarithmic. Every 10 dB reduction halves the subjective loudness. A 38 dB unit doesn't sound 27% quieter than a 30 dB unit — it sounds noticeably less than half.
What changes Rw — the three levers
- Pane thickness asymmetry. 4-16-4 has matched resonance frequencies — sound passes through. 6-16-4 mismatches them and adds 3-4 dB.
- Acoustic-PVB laminate. A tri-layer viscoelastic interlayer (Saflex Q-series, Trosifol SC) damps the coincidence dip around 2-3 kHz — adds 3-6 dB on the same glass build.
- Cavity width. 20mm cavity outperforms 16mm acoustically (the reverse of thermal). 24mm cavity adds another 1-2 dB. Beyond 30mm the curve flattens.
Laminated DG vs triple — when does triple win?
For traffic and speech noise (the 500 Hz-2 kHz band where most pain lives), acoustic-PVB laminated DG matches or beats triple — it's lighter, lower-cost, and the right answer 70-80% of the time. Triple wins where the noise has strong low-frequency content (large trucks, train rumble, aircraft jet roar) because the third pane and second cavity extend the damping at 50-250 Hz. For Heathrow approach lines, triple acoustic is the gold standard.
Acoustic glass — common questions answered
Q: How much quieter will it actually sound?
Honest answer: depends on the noise spectrum and the rest of the building envelope. Going from a 30 dB Rw standard unit to a 38 dB Rw acoustic unit on a typical residential window gives a subjective halving of perceived loudness — sleep through the freight train, hold a phone call beside the window, don't notice the late-night traffic as background noise. Going from 38 dB to 44 dB triple is another perceived halving. But: trickle vents, letter boxes, chimney flues, and gappy front doors all flank the glazing — fix those at the same time or the windows over-perform relative to the room.
Q: What's the difference between Rw, Rw+C, and Rw+Ctr?
Rw is the single-number rating averaged across the full speech/music spectrum. C (spectrum adaptation term) re-weights for pink-noise / general speech / aircraft. Ctr re-weights for low-frequency dominant noise (traffic, train rumble, music bass). For a window facing a busy road, look at Rw+Ctr — it's typically 5-7 dB lower than Rw. An "Rw 42 dB" unit might be "Rw+Ctr 36 dB" against road traffic. We surface both numbers on the spec sheet.
Q: Will acoustic glass also help with thermal performance?
Yes, partially — but the optimisation is different. Thermal performance loves a 16mm cavity (the dead-air sweet spot for argon convection); acoustic performance loves 20-24mm. Thermal loves matched panes; acoustic loves asymmetry. The compromise spec — 6.4mm acoustic-PVB outer + 16mm argon cavity + 4mm low-E inner — gives around 40 dB Rw and a 1.3 W/m²K U-value, which hits both Approved Document L energy and Approved Document E noise targets in one unit. The configurator will quote this as the default "acoustic + low-E" build.
Q: I have MVHR / mechanical ventilation. Do I still need trickle vents?
Excellent question and the answer is the single best argument for MVHR in noise-heavy properties. If you have a working MVHR system providing the Approved Document F ventilation rate, you do not need trickle vents in the window — and removing trickle vents typically doubles the real-world acoustic performance of an acoustic unit (a 42 dB Rw window with a trickle vent often performs at 32-34 dB on site). If MVHR isn't in the plan, specify acoustic trickle vents (10-15 dB Dn,e,w rating) rather than standard ones, and accept around 3-4 dB on-site loss.
Q: Can I get acoustic glass in toughened or safety form?
Yes — acoustic-PVB laminated glass is already safety-rated to BS EN 14449 (the PVB interlayer holds the shards). For ground-floor or door applications you can pair it with a toughened outer pane for the full acoustic-laminated + toughened combo: the outer toughened pane meets the BS EN 12150 critical-location requirement, the inner acoustic-PVB laminated pane gives the dB performance and the laminated-glass retention benefit. This is a popular spec for ground-floor city-centre apartments, hotel guest rooms, and street-facing offices.
Q: Does it work for upstairs noise / neighbour music / barking dogs?
For airborne noise (music through a shared wall, voices through a party wall): glazing won't help — the noise transmits through the wall, not the window. For airborne noise through windows (neighbour's stereo with the window open, late-night street talkers, dawn chorus): acoustic glass works very well. For impact noise (footfall above): glazing irrelevant — that's a structural-floor problem. We're happy to triage by phone if you're not sure where the noise is getting in — call the helpline and describe the source.
Q: How much more expensive is acoustic glass than standard DG?
Rough order: +30% for a 38 dB asymmetric DG (cheapest entry), +60% for a 40-42 dB acoustic-PVB DG, +120% for a 44 dB+ triple acoustic stack over an equivalent-size standard 4-16-4 unit. The configurator quotes live — you can pick the dB-target and see the price step. For most homeowners on a noise problem the 40-42 dB sweet spot delivers the most subjective improvement per pound spent.
Q: What's the lead time and warranty?
Acoustic-PVB laminated DG: 10-14 working days. Triple acoustic stacks and bespoke: 14-21 working days. Every unit carries a 10-year edge-seal warranty, 5-year PVB lamination warranty, and a BS EN ISO 10140 lab-measured Rw certificate on request (specify at order). UKCA and BS EN 12758 Declaration of Performance on request.
Related guides and specifications
Don't guess — match the dB target to the noise source
Call 0117 330 3057 (08:00-18:00 Mon-Fri) with your noise source (road / rail / aircraft / plant) and we'll spec the right build. Or send a noise survey for a planning-condition quote.