Up to 42 dB Rw · Sleep with the Window 'Open' · From £595 per window
Edinburgh's main-road tenements — Leith Walk, Lothian Road, London Road, Newington, Gorgie Road, Dalry Road — suffer 60–75 dB of traffic noise at the window. Acoustic-laminate glazing combined with brush-pile draught-proofing cuts that to 25–35 dB inside the room, quiet enough to sleep comfortably with the bedroom blackout drawn. Three solutions: acoustic secondary glazing, acoustic slim-line double glazing, or acoustic triple-glazed casement.
Standard 4mm float glass reduces noise by about 28 dB Rw. Two parallel panes of the same thickness behave like a tuning fork at certain frequencies and the noise reduction at those frequencies drops dramatically — which is why bog-standard double glazing is often disappointing for traffic noise. Acoustic-laminate glass uses two panes of differing thickness (typically 4mm + 6mm) bonded with a viscoelastic PVB interlayer that damps the resonance. Result: consistent 36–42 dB Rw across the whole frequency range, especially in the traffic-noise band (low-mid frequencies).
For a road-facing Edinburgh tenement flat, secondary glazing with 6.4mm acoustic-laminate glass fitted 100–150mm behind the original sash gives the best noise reduction of any heritage glazing option — 38–42 dB Rw. The wide air gap between the two panes is what does the work; you can't get this kind of acoustic separation in a single sealed unit. It's also reversible and listed-building-friendly. Cost: from £595 per window for 6.4mm acoustic in aluminium frame.
When secondary glazing isn't visually acceptable (open-plan studio flats, period interiors where the secondary frame would look wrong), acoustic-laminate slim-line double-glazed units retrofit into the original sash rebate. Performance: 33–36 dB Rw — not as good as secondary glazing but a major improvement on the 28 dB of standard glazing. Cost: from £685 per sash.
For new-build replacement work outside conservation areas, A+ triple-glazed casements with acoustic-laminate outer pane give 38–40 dB Rw with the additional benefit of a 0.9 W/m²K thermal U-value. Cost: from £1,295 per window. This is the right answer for road-facing rear extensions, mansard conversions and new infill housing.
Air leakage matters more for noise than people realise. A 1cm gap around a sash leaks as much sound as a 30cm × 30cm hole in plain glass. Acoustic-laminate glazing without brush-pile draught-proofing typically gives 8–10 dB less real-world performance than the lab spec. We always quote acoustic glazing and full draught-proofing as a single package — the combination is what actually makes the bedroom quiet.
From £595 per window for 6.4mm acoustic secondary glazing in aluminium frame, £685 per sash for acoustic slim-line double glazing retrofit, £1,295 per window for A+ triple-glazed acoustic casement. Combined acoustic-and-draught-proofing package: £840 per pair of sashes. 10-year sealed-unit warranty.
Listed-building paperwork sorted for us, original sashes saved, and the front room is no longer a wind tunnel. Brilliant from quote to completion.
James & Catriona R., Stockbridge EH3 — Sash & case restoration + secondary glazing · 5/5 ·
Quietest the house has ever been. Bay windows look stunning, and the survey caught a lintel issue two other firms missed.
Rachel B., Trinity EH5 — Triple glazing — full house · 5/5 ·