Arrange the compliance strategy before construction, not only when a completion certificate is requested. [1] [2]
What sound testing addresses
Approved Document E sets out requirements and guidance for resistance to the passage of sound. For new adjoining homes and flats, the relevant separating walls and floors need an appropriate compliance route. Airborne sound and impact sound are different aspects of performance; a wall and a floor do not necessarily require the same tests. [1]
The testing arrangements should be agreed with the building control body for the particular development. Do not assume that every new detached house requires the same separating-element tests as a block of flats, or that testing one room proves every element in a varied scheme. [1]
Ask the acoustic specialist to identify the constructions, junctions and test locations that matter. Keep the specification consistent through procurement and installation so the completed building reflects the design being assessed.
When Robust Details can be used
For eligible new-build construction, the recognised Robust Details route can provide an alternative to pre-completion sound testing of the relevant separating elements. It requires the appropriate registered details, plot registration and notification arrangements, and construction in accordance with the specified detail. A generic drawing labelled “robust construction” is not that route. [1]
Decide this before starting. A late decision to change a separating wall or floor can affect the compliance route, so obtain advice before substituting materials or altering junctions. Where the route's conditions are not met, testing may be needed. [1]
Air-tightness testing is a Part L check
Under the 2021 Part L dwelling guidance incorporating the 2023 amendments, every new dwelling should be pressure tested. The measured air permeability feeds into the as-built energy assessment. The result must work with the other energy-performance requirements; there is no single project-independent target that can replace the dwelling's assessed design. [2]
The guidance requires competent testing, appropriate equipment and reporting. It also requires the building control body to receive the test results, including failed tests. A poor result cannot simply be discarded in favour of the design-stage assumption. [2]
For higher-risk building work, the relevant Future Homes and Buildings Standards provisions commence on 24 September 2027, subject to separate application-based transitional arrangements. This is distinct from the general 24 March 2027 commencement. [3]
What happens when a result is unsatisfactory?
Agree the investigation and remedial work with the relevant specialist and building control body. For air leakage, the Part L guidance provides for improvements and retesting where necessary. For sound, the tested separating construction and its associated details need to be assessed against the required performance. [2] [1]
Allow time in the programme for that process before final certification. The aim is to demonstrate the completed construction, not merely to collect a certificate with the project's name on it.
Keep a coordinated completion record
Retain the sound-test reports or Robust Details evidence, pressure-test report and updated energy calculation together. Match the results to the correct dwellings and drawing revisions. The evidence should make it possible to see what was tested and which compliance route was used. [1] [2]
The Future Homes Standard takes effect from 24 March 2027, subject to transitions and separate HRB arrangements. Confirm the relevant Part L edition for the project rather than carrying a testing specification into the new regime without checking it. [3]