Do I Need Part E Sound Testing for a Flat Conversion? (2026 UK)
If you're converting a house into flats, or otherwise creating new homes by change of use, Approved Document E (Building Regulations) applies. For conversions you almost always need pre-completion sound testing (PCT) to prove the separating walls and floors meet the required dB targets for airborne and impact sound. New-build can instead use a Robust Detail to skip testing. Here's how it works in 2026.
Part E sound testing — quick answer
- Converting a house to flats: Part E applies — pre-completion testing usually required
- Airborne target (conversions): at least 43 dB DnT,w + Ctr (walls & floors)
- Impact target (conversions, floors): no more than 64 dB L'nT,w
- New-build alternative: use a registered Robust Detail to avoid testing
- Who tests: a UKAS-accredited or ANC-registered sound tester
- Sample testing: typically one set of tests per group of similar separating elements
Build the acoustic separation in from the start. Failing a Part E test after completion means opening up finished walls/floors to fix them — far more costly than designing the separating structure correctly and testing once at the end.
Approved Document E sound targets, 2026 UK
Conversions = material change of use; new-build targets are slightly higher.
When Part E and sound testing apply
Approved Document E applies whenever you create new dwellings — including converting a house or other building into flats (a 'material change of use'). For conversions, you almost always need pre-completion sound testing (PCT) of the separating walls and floors to prove they meet the airborne and impact targets. Your Building Control body confirms the sampling — typically one set of tests per group of similar separating elements rather than every wall and floor.
Higher is better for airborne (you want a big dB number); lower is better for impact (you want few dB of footstep noise getting through).
Robust Details, testers and what failing costs
Robust Details are an alternative to testing — but only for new-build separating walls and floors. Register a recognised detail, build it exactly to spec, and you skip the test. Conversions cannot use Robust Details and still require PCT. Testing is carried out by a sound tester accredited by UKAS or registered with the ANC, who issues a report your Building Control body accepts as evidence.
If a conversion fails, you must upgrade the element (added mass, an independent lining, a floating floor) and re-test — disruptive and costly once finishes are in. Build the separation to a proven specification from the start. To get it right, understand the noise types in airborne vs impact noise, price the work with the cost guide and calculator, or engage a vetted installer via our free quote service.
Get Part E-Compliant Soundproofing Quotes
Converting to flats? Our vetted acoustic installers build separating walls and floors to meet Part E — and can arrange the pre-completion sound test. Free quotes, no obligation.
Frequently asked questions
Related Guides
More guides to help you plan and budget.
Sources used in our 2026 figures
- gov.uk — Approved Document E (resistance to sound)
- ANC — Sound testing registration scheme
- Robust Details Ltd — new-build separating structures
Methodology: Compliance guidance reflects Approved Document E (England & Wales, current June 2026); always confirm sampling and targets with your Building Control body. Last updated .