Pre-Completion Sound Testing

What Is Pre-Completion Sound Testing?

Pre-completion sound testing (often called Part E testing) is the on-site measurement of sound insulation between new dwellings once the separating constructions are complete and the rooms are close to finished. It confirms that walls and floors between homes perform as the Building Regulations require, rather than relying on the design alone.

Two types of test are carried out. Airborne tests measure how well a wall or floor stops sounds such as voices, television and music. Impact tests use a standard tapping machine on the floor above to measure how much footfall and impact noise reaches the room below.

When Do You Need Testing?

Testing is needed where new dwellings share a separating wall or floor, including apartments, duplexes, semi-detached and terraced houses, and rooms for residential purposes such as student accommodation and hotels, depending on the jurisdiction. In Ireland it supports the evidence the assigned certifier needs to certify compliance with Part E. In England, Wales and Northern Ireland it is the evidence building control expects on completion.

Testing is carried out towards the end of construction, but the best time to plan it is at the start. Agreeing the test schedule early means plots are ready when the test team arrives and any problems are found while there is still time to fix them.

What We Do

Test schedule: we agree the number and location of tests with the design team and certifier or building control, covering each separating construction type.
Site inspections: visits during construction to check details that commonly cause failures, such as flanking paths, junctions, service penetrations and workmanship.
Airborne and impact testing: measurements to the relevant ISO methods, with results rated and compared against the applicable performance standard.
Remedial advice and retesting: if a test fails, we identify the likely cause, advise on a practical fix and retest once the work is done.
Test reports: clear reports for the assigned certifier or building control, ready for sign-off.

On larger schemes, we recommend testing the first completed plots of each construction type early. A pass gives confidence to carry on, while a failure can be traced and the detail corrected before it is repeated across the whole development. This staged approach is usually far cheaper than finding a systematic problem when most of the units are finished.

Our Approach

We confirm the test schedule and access arrangements with the site team, then issue a short checklist so rooms are ready: doors and windows fitted, floor finishes as designed, trickle vents closed and the site quiet during testing. On the day, our consultants measure airborne and impact performance across the agreed pairs of rooms and give an initial indication of results on site.

Results are calculated and checked, then issued in a formal report. Where a result falls short, we discuss it with you straight away so remedial work can be planned without holding up the programme.

Standards and Guidance

Ireland: Technical Guidance Document E (TGD E), 2014, Sound. Separating walls and floors need an airborne DnT,w of at least 53 dB, and separating floors an impact L’nT,w of no more than 58 dB.
England and Wales: Approved Document E, Resistance to the Passage of Sound, which rates airborne performance as DnT,w + Ctr.
Northern Ireland: Technical Booklet G, Sound.
Measurement: I.S. EN ISO 16283-1:2014 (airborne) and I.S. EN ISO 16283-2:2020 (impact).
Rating: I.S. EN ISO 717-1:2020 (airborne) and I.S. EN ISO 717-2:2020 (impact).

What You Receive

Each test report sets out the dwellings and rooms tested, the constructions involved, the measured and rated results, and a clear pass or fail against the applicable requirement. Reports are prepared to be accepted by the assigned certifier or building control. Where retests are needed, the updated results are reported in the same format so the compliance record is complete.

We also keep the test schedule up to date as testing progresses, so the design team, contractor and certifier can see at a glance which plots have been tested, which have passed and what is still outstanding before handover.

Common Issues and How We Avoid Them

Most failures come from small details rather than the main wall or floor build-up. Typical causes include gaps at the head of separating walls, unsealed service penetrations, back-to-back sockets, rigid connections between floating floors and walls, and flanking through lightweight internal walls or façade cavities.

Our site inspections target these points before finishes go on, when they are cheap to put right. Where our team also designed the separating constructions as part of our building acoustics work, we check that what is built matches what was specified.

Why Wave Dynamics

Our sound insulation testing is SITRI and SITMA certified, and we test in Ireland, Northern Ireland and Great Britain, so one team can cover developments across all three. Because the requirements, rating parameters and sign-off routes differ between jurisdictions, we make sure each report uses the right criteria and suits the person who has to accept it. We combine testing with design and site advice, which means we can explain why a result is what it is and how to fix it, not just report a number. For other test types see our sound insulation testing and acoustic testing services.

Frequently Asked Questions

Which buildings need pre-completion sound testing?

New dwellings with a separating wall or floor between them usually need testing, including apartments, duplexes, semi-detached and terraced houses. Depending on the jurisdiction, rooms for residential purposes such as student bedrooms and hotel rooms, and dwellings formed by material change of use, can also need testing. We confirm the scope with your certifier or building control.

What needs to be in place on site before testing?

Rooms should be complete apart from decoration: separating walls and floors finished, doors and windows fitted and closable, and floor coverings as designed. Electricity should be available, rooms should be empty of materials where possible, and noisy work nearby should stop during measurements. We send a checklist ahead of each visit.

Can Robust Details be used instead of testing?

In England and Wales, house builders can register new homes with Robust Details Ltd and build to approved separating wall and floor designs as an alternative to pre-completion testing. The details must be registered before work starts and built exactly as specified. The scheme does not apply in Ireland, where testing to TGD E is the norm.

How many tests are needed on a development?

It depends on the number of dwellings, the separating construction types and the requirements of the certifier or building control. Approved Document E, for example, sets a sampling rate based on groups of similar dwellings. We propose a schedule that covers every construction type and agree it before testing starts.

What happens if a test fails?

We review the result against the construction and look for the likely cause, often a flanking path or a detailing fault. We then advise on a practical remedy and retest once it is complete. Where the same construction is used elsewhere, the fix may need to be applied more widely, so early tests on representative plots are useful.

Is a lower result acceptable if the room is still unfinished?

No. Results reflect the building as tested, so testing incomplete rooms can produce misleading results in either direction. Missing doors, open service holes or absent floor finishes all change the outcome. It is better to wait until rooms are properly ready than to test early and risk a failure that has to be repeated.