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If you’re planning a new build, conversion, or residential development, sound insulation testing is a legal requirement under Part E of the Building Regulations. This guide covers what the rules actually require, which properties need testing, the standards you need to hit, and how to get your site ready. If you need a test booked, our sound insulation testing service covers Sussex, Surrey and Kent with UKAS-accredited engineers and certification within two days.
Get in touch with our team of experts today on 01403 253439
How long has sound insulation testing been a legal requirement?
Sound insulation testing has been mandatory for qualifying properties since 1st July 2003, extending to new build developments from 1st July 2004. It applies under Part E of the Building Regulations, which governs “resistance to the passage of sound” between separate dwellings.
Which properties need sound insulation testing?
You’ll need to arrange testing if your project involves:
- New build developments with two or more properties
- Conversion of a single property into flats
- Buildings such as hotels or nursing homes used for residential purposes
- Commercial new builds involving separating walls or floors
- Builds that don’t follow Robust Details construction methods
Detached properties, and internal walls or floors within a single dwelling, are exempt. If you’re not sure whether your project qualifies, it’s worth checking before you finalise your build plans rather than after.
What standard do you need to reach?
Part E sets minimum performance levels for both airborne and impact sound insulation. For a quick reference:
| Area | Airborne sound insulation (minimum, dB) | Impact sound insulation (maximum, dB) |
|---|---|---|
| New build walls | 45 | – |
| New build floors | 45 | 62 |
| Conversion walls | 43 | – |
Airborne testing measures how much sound is transmitted through walls and floors when noise is generated on one side; impact testing measures noise transmitted by impact, such as footsteps, using a standardised tapping machine. For a full breakdown of how each type of test works, see our guide to airborne versus impact sound.
When is your site ready for testing?
Testing has to happen before completion, but the property doesn’t need to be entirely finished. As a minimum, your site should be at second fix stage, meaning:
- Internal doors and windows are fitted and operational
- Walls, floors and ceilings are complete
- Rooms due for testing are empty and clear of building mess
- Ventilation systems are installed
- Light switches and sockets are fitted
Getting this wrong is one of the most common causes of delayed testing, so it’s worth confirming site readiness with your testing provider before booking a date.
How many tests will my development need?
The number of tests required depends on the number of dwellings, the separating walls and floors involved, and the layout of the build. As a general rule, a minimum of 10% of properties in a development must be tested, though this varies by project. A qualified assessor can confirm the exact number for your site during planning.
What happens if a property doesn’t meet the standard?
If a test doesn’t meet the required dB levels, remedial work is needed before the property can be retested and signed off. This can mean added cost and delay, particularly if issues are only picked up close to completion, which is why getting expert input at the planning stage matters more than most developers expect. Good sound performance also has a knock-on benefit at resale. See our article on how sound insulation affects property value for more on that.
Get your testing booked early
The earlier a qualified tester is involved in your project, the less likely you are to face delays or failed tests further down the line. Book a sound insulation test with our UKAS-accredited team, or get in touch for advice on what your specific development will need.