Sound testing for Part E
Pre-completion sound insulation testing checks that separating walls and floors between homes meet Approved Document E. TestConnect books accredited sound testers, keeps the sets of tests organised by group, and records every result against the plots tested.
What is measured
Sound tests are carried out between pairs of rooms on either side of a separating wall or floor.
- Airborne sound insulation (voices, television) is reported as DnT,w + Ctr in decibels. Higher is better, and the standards are minimums.
- Impact sound insulation (footsteps on the floor above) is reported as L'nT,w in decibels, for separating floors only. Lower is better, and the standards are maximums.
Performance standards
Approved Document E (2003 edition incorporating 2004, 2010, 2013 and 2015 amendments), Tables 0.1a and 0.1b:
| Type | Element | Airborne DnT,w + Ctr (minimum) | Impact L'nT,w (maximum) |
|---|---|---|---|
| Purpose-built houses and flats | Walls | 45 dB | – |
| Floors and stairs | 45 dB | 62 dB | |
| Houses and flats formed by material change of use | Walls | 43 dB | – |
| Floors and stairs | 43 dB | 64 dB | |
| Purpose-built rooms for residential purposes | Walls | 43 dB | – |
| Floors and stairs | 45 dB | 62 dB |
How many tests
Approved Document E, Section 1, describes a programme of pre-completion testing on a sample of homes:
- A development is split into groups (houses, flats, rooms for residential purposes), and into sub-groups where the separating wall, floor or flanking construction differs.
- One set of tests is carried out between the first homes scheduled for completion in each group or sub-group, then, assuming none fail, at least one set for every ten homes in the group or sub-group (paragraphs 1.29 and 1.30).
- A set is normally two airborne tests for houses; four tests (two airborne, two impact) for flats with a separating floor only; and six tests (four airborne, two impact) for flats with both a separating wall and floor.
- Testing should be more frequent early in a run of completions, so problems are caught early.
When to test
Tests are carried out once the homes on either side of the separating element are essentially complete, apart from decoration. Impact tests are done without soft floor coverings such as carpet or foam-backed vinyl (paragraph 1.10).
If a set of tests fails
A set fails if any individual test doesn't meet the standard. Remedial treatment should be applied, the developer should show building control that other rooms and homes sharing the construction meet the standard, and the rate of testing should increase until building control is satisfied the problem is solved (paragraphs 1.32 to 1.39).
Robust Details
For new houses and buildings containing flats, Regulation 41 testing does not apply to separating walls and floors built to a design detail approved by Robust Details Ltd, provided building control is notified with the detail and its unique number, and the work follows the detail. Some separating structures can use Robust Details while others are tested.
Who carries out the tests
Approved Document E says the test body should have appropriate third-party accreditation, preferably UKAS accreditation for field measurements, and that members of the ANC Registration Scheme are regarded as suitably qualified (paragraph 0.4). The results must be given to building control (Regulation 41).
This is a summary of published guidance, not compliance advice. Your building control body sets the testing programme for a development; check anything you're unsure about with them. This page covers England.
How TestConnect helps
- Post sets of tests per group, or let your assessor post them, to sound testers who cover the area.
- Readiness checks before each visit, so rooms on both sides are ready.
- Results recorded per pair of rooms, with fails, remedial notes and retests kept.
- Reports and certificates uploaded against the plots tested.
Read the full guide: Sound testing: what Part E needs.
Sources
- Approved Document E: resistance to the passage of sound (GOV.UK)
- The Building Regulations 2010, Regulation 41: sound insulation testing (legislation.gov.uk)
- Designing Buildings Wiki: pre-completion sound testing
Last checked: October 2026.