New-Build Apartments: When Modern Glazing Still Isn't Quiet
It surprises owners of five-year-old apartments that their windows are noisy. The explanation is straightforward: a standard sealed double-glazed unit is optimised for thermal performance, and the design choices that achieve that are actively unhelpful acoustically.
Why a modern sealed unit underperforms on noise
A typical unit uses two panes of equal thickness separated by a 16–20 mm gap. Equal thicknesses mean both panes share the same coincidence frequency, so their weak points coincide instead of covering each other. And a 16 mm gap is far too small to provide meaningful decoupling — it behaves closer to a stiff spring linking the panes than to an acoustic break.
- Equal pane thicknesses align the weak points
- 16–20 mm gap gives minimal decoupling
- Argon fill helps thermally, not acoustically
What a secondary layer adds that the unit cannot
Adding a room-side panel at 75–100 mm gives the deep air gap the sealed unit does not have, and introduces a third, deliberately mismatched thickness. The improvement on top of existing double glazing is typically substantial, particularly against road and rail.
Trickle vents are usually the flanking path
New-build apartments almost always have trickle vents in the head of the frame. These are frequently the dominant noise path once the glass is dealt with — occasionally even before. Any specification for a new-build has to address the vent as well as the glass, or the money is wasted.
Consent in a managed block
The install is internal and reversible, so most managing agents consent readily. Ask in writing and keep the reply; we will provide a specification sheet for the application.
Frequently asked questions
For noise, yes — often dramatically. For heat, the gain is smaller because the existing unit is already reasonable.
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