49dB Secondary for Sash Windows Installation
Prince Albert Road, NW1 – master bedroom quieted with our 49dB secondary windows
Location context - why this room was noisy
The A5205 (Prince Albert Road) is a busy distributor between Maida Vale and Camden Town, serving attractions like London Zoo and carrying bus route 274.
Historic DfT traffic counts list Prince Albert Road ~21k AADT (well above the 10k vpd threshold often used to flag high-flow urban links). DEFRA’s 2022 strategic noise maps show elevated Lden along London A-roads due to persistent flows, with evening/weekend visitation maintaining levels. Camden’s borough-wide 20mph limit moderates risk, but volumes remain high—creating steady mid-band energy with rush-hour peaks that secondary glazing is designed to address.
Property
Victorian house near Regent’s Park, NW1 – master bedroom
Existing Windows
Original single-glazed timber sash
Challenge
Constant road noise from Prince Albert Road is disrupting rest and home working
Solution
Bespoke timber secondary sash system with 49dB acoustic glass
Result
Indoor measurements:
- LAeq: ~40.8dB → < 28.5dB (≈12dB reduction)
- LAFmax: 52.9dB → 32.4dB (≈20.5dB reduction)
- Spectrum: strong cuts across 125Hz–4kHz, taming traffic rumble and tyre/engine noise (Measured with an NTi XL2, same mic position before/after.)
Why secondary glazing (not replacement)?
PLANNING
Heritage friendly – original sash retained; minimal external change.
Acoustic Headroom
49dB acoustic laminate + tuned air-gap delivers exceptional attenuation, especially at 125–500Hz.
Thermal & Comfort Gains
Lower drafts and a major thermal step-up – single glazing ~U-value 5.6W/m²K; our secondary specification delivers calculated U-values below ~0.9 W/m²K for the internal unit, dramatically improving winter comfort.
Reversible & Serviceable
Future-proofed without altering the façade
OUR SOLUTION
- System: Bespoke timber secondary window (inward-opening) for sash built to mm accuracy
- Glazing: 49dB acoustic laminate (lab rating) with deep, tuned air-gap
- Sealing: Multi-point compression seals to suppress leakage paths
- Finish: Painted to match the interior; slim sightlines to preserve light
Hear the Difference
Headphones recommended.
Acoustician Note
“Standing in the bedroom after we closed the secondary sash, the rush-hour murmur just fell away. The meter showed LAeq dropping from ~41dB to below 29dB, but what you notice is the calm—no sharp peaks, just quiet. And my favourite part is that nothing outside changed—the heritage sash stays—but inside it’s a different space: warmer, quieter, and finally good for sleep and Zoom.”
– Sebastian, Lead Acoustician, The Soundproof Windows
Specification Snapshot
- System: Timber secondary window for sash (bespoke)
- Acoustic glazing: 49dB laminate (laboratory rating)
- Measured result: LAeq ↓ ≈12dB, LAFmax ↓ ≈20.5dB (indoors)
- Thermal: From ~U 5.6 (single) to < 0.9W/m²K (internal secondary unit)
- Guarantee: 10-year insurance-backed (CPA)
Thinking about a similar room?
If your bedroom or home office faces a busy London A-road, 49dB secondary glazing can deliver a 10–20dB indoor reduction while keeping your original sash.
Book a consultation → We’ll take measurements, model your noise profile, and propose the right configuration.
SPECIALIST SOUNDPROOF WINDOWS & DOORS
Through specialist manufacturing and precision technology, we can reduce noise pollution by up to 95%. By installing specialist soundproof windows and doors, we provide you with the best products on the market. Don’t compromise on design. Don’t compromise on quality.
PROUDLY SUPPORTING:
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10 YEAR INSURANCE BACKED GUARANTEE
All of our products come with up to a 10 Year Insurance Backed Guarantee provided by the Consumer Protection Association. So you can rest assured that your home is in safe hands.
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AWARD-WINNING PRODUCTS & INSTALLATION
Following awards in 2020, and 2021, The Soundproof Windows was announced as the ‘Best Acoustic Window & Door Installation Company – London’ at the SME News Awards 2022.