For anyone who has attempted to sleep under a flight path from Heathrow airport, or has lived next door to a busy bus route in a Victorian terraced house, there will be a sense of familiarity with noise. You can insulate your loft. You can install carpet on the floors. However, no matter how hard you try, the windows always seem to allow the noise in. And in a conservation area, the obvious fix, ripping out the sashes and installing chunky uPVC double glazing, is neither permitted nor desirable.
This is the gap that The Soundproof Windows occupies. Based in Battersea and working across London, the family-run firm designs and installs bespoke timber acoustic windows and doors for period homes, listed buildings, conservation areas, recording studios and new builds. We looked at their approach, their track record and their limitations to see whether the specialism justifies the premium.
What The Soundproof Windows Actually Do
The Soundproof Windows is not a glazing business with an acoustic option bolted on. It is an acoustics business that manufactures windows. This difference may appear to be trivial, but it does matter.
Their product line includes: soundproof sash windows, mock sash windows for use when the original openings have already been removed, casement and tilt-and-turn windows, high-performance secondary windows and soundproof front, French and patio doors. Everything is handmade in timber, using hard and softwoods treated against swelling, warping and fungal attack. The Soundproof Windows is FENSA registered, TrustMark registered, enrolled on Trading Standards’ Buy With Confidence scheme, and won the award for Acoustic Window & Door Installation Company in London at the SME News Awards 2022 after receiving awards in 2020 and 2021.
Engineer-Led Soundproofing, Not Just Thicker Glass
What makes The Soundproof Windows so interesting is how they go about doing things. Most glazing companies start by creating a product, and then try to find ways to apply that product to clients’ problems. On the other hand, The Soundproof Windows starts with a diagnosis.
The first step before you get into specifications is to establish the decibels and character associated with your specific noise environment. For example, aircraft noise, road traffic noise, railway rattle and social noise from next door can be treated very differently. A low-frequency “bass” noise from a late-night bus leaving and the high-pitched whining sound of an incoming plane are examples of different types of acoustic issues and would require different products to solve the problem. Once the decibel level and character of the disturbance are established, the specification follows: Glass thickness, the distance between panes of glass, the construction details of the timber frame surrounding the glass, and the seals around it.
The company publishes project case studies with the acoustic rating achieved on each job, from 43dB conservation sash windows in Nunhead to 59dB studio windows in Regent’s Park, making the case for engineer-led soundproofing. The acoustic requirement determines the product, not the other way round.
Heritage-Sensitive Noise Reduction
This is exactly where The Soundproof Windows shines: in conservation areas as well as listed buildings. These types of projects can be tricky to get right. It can be expected that planners will look at the sight lines, glazing bar detail, horn detail, and the reveal detail as well. Unfortunately, standard acoustic glazing is too heavy and too deep to pass muster on all these aspects.
The Soundproof Windows designs and manufactures acoustic sash windows for conservation areas. These products replicate the original joinery profile, with the acoustic build-up concealed within it. Where replacement is not an option at all, their high-performance secondary windows are a distinct product from the flimsy secondary glazing usually sold under that name, and the company maintains a detailed comparison of the two on its own site rather than blurring the distinction. Additionally, they provide general information regarding obtaining planning approval and will assist you during the application process. This suggests that they have gone through the process enough times to develop a consistent methodology.
There is a pleasing absence of hard sell throughout. The website hosts a noise evaluation tool, a remote estimate service for measuring your own windows, and long-form guides on acoustic ventilation, condensation and laminated glass thermal stress. Some of that content actively explains where soundproofing underperforms. Companies confident in their product tend to write this way. Companies that are not tend to write brochures.
Pros and Cons
Pros
Diagnosis precedes specification. The noise source is assessed and characterised before anything is proposed, so you are buying a solution rather than a catalogue item.
Genuine heritage credentials. Timber joinery made bespoke to fit into listed buildings and conservation areas. Planning support is offered as part of the service rather than left to the homeowner.
Published performance figures. Case studies state the acoustic rating for each installation, from 42dB front doors to 59dB studio windows.
Substantial protection. There is an insurance-backed guarantee of up to 10 years from the Consumer Protection Association, along with TrustMark, FENSA and Buy With Confidence registrations.
Thoughtful extras. Trees are planted with Trees for Life on every installation, restoring native woodland in the Scottish Highlands, and the online noise tool and remote estimate service are free to use before any commitment.
Cons
This is not a budget option. Handmade timber acoustic units cost meaningfully more than off-the-shelf double glazing, and the site does not lead with prices, though a costs page exists.
Bespoke means waiting. Handmade joinery, particularly for heritage properties requiring planning consent, takes longer than a standard installation.
Geographically focused. The business is London-centred, which is sensible given where the noise problems are, but limits the offering elsewhere.
Closing Thoughts
Very few companies doing work in this market have their primary business as acoustics. The rest are primarily glazing companies that offer an acoustic product line. This is easily seen when the involvement of either a conservation officer, a bay window with a unique reveal, or a noise source that doesn’t fit into the obvious solution shows up on a project.
The Soundproof Windows has built its business around this difference; acousticians specify, skilled craftsmen build, and the architecture remains intact. It will cost you more and take longer. But for those who want to solve a severe noise problem within a traditional London home, they are the team to call.
