APT Sound Testing Article

Part E Sound Testing in London

We have undertaken hundreds of sound tests in London. We also offer robust and cost effective acoustic design advice to ensure your compliance with Part E of Regulations. Our usual pathway for successful sound testing is:

1. Our Acoustic Design Service

2. Acoustic Site Audits 

3. Pre-completion Sound Testing

Acoustic Design Service

On our experience some of the most common mistakes during the construction are as follows: 

  • Using lightweight blocks in the inner envelope construction as sound will travel along light block-work both vertically and horizontally from dwelling to dwelling.
  • The use of resilient suspended ceilings will help improve the performance of the floor partition.
  • Not incorporating a high quality resilient acoustic membrane on top of the floor to improve the impact performance of a floor. 
  • Ensuring all penetration’s are fully sealed where they terminate through floors and they are adequately boxed with acoustic quilt and two layers of plasterboard. 

Acoustic Site Audits

We can undertake acoustic site audits, to let us view the existing site construction. This allows us to check for potential problematic areas such as the inclusion of lightweight blocks within the existing wall construction. It also lets us check that the installation teams are installing the acoustic materials as per manufacturer’s guidelines, thus avoiding crucial onsite mistakes. In our experience a sound test failure is often due to the poor workmanship rather than the actual design. The site survey visits negate the risk of sound test failure. 

We can also undertake sample sound testing of the existing construction. This offers an accurate overview of the acoustic performance of the existing partitions, which enables us to offer a targeted acoustic design which takes into account the performance of the existing construction. 

Defect Diagnosis & Remedial Advice 

With many years’ experience in building acoustics, we are able to diagnose the reasons for the sound test failure and recommend a cost-effective solution. Often, the reasons for the partition failure are obvious to the test engineer in which case the advice will be minimal and subsequently the cost for acoustic design advice will be minimal. Sometimes, there are more technical issues which require more detailed diagnosis and invasive investigation, such as large amounts of noise flanking due to serious design faults, e.g. poor material isolation. 

Pre-completion Sound Testing

To help enforce good acoustic design principles pre-completion sound testing was introduced July 2003, this resulted in all new build properties and conversions which were built after this date are require 10% of each party wall/floor construction type to be tested. 

Pre-completion Sound Testing is carried out between pairs of rooms separated by party walls or floors. The two ‘habitable’ areas that usually require sound testing are living rooms and bedrooms, although other rooms can be tested if this is not possible, i.e. kitchen to bedroom. Here is a quick description of the tests:

Airborne Sound Tests 

Airborne Sound Tests may be required between horizontally and vertically separated pairs of rooms. The sound tests are undertaken by using a sound source, amplifier and loudspeaker to generate a high noise level in one room (the source room). Noise measurements are then taken in both the source and receiver rooms using a prescribed number of source and microphone positions.

Impact Sound Tests

For vertically separated rooms, an Impact sound testing may also be required. This sound test is undertaken using a “tapping machine”, (as above) which drops a series of weights onto the floor of the upper room. The noise level in the lower (receiver) room is measured for a prescribed number of source and microphone locations. The background levels in the receiver room are measured and the reverberation time in the receiver room is also measured. 

Required Sound Test Levels 

The Building Regulation Part E set minimum performance requirements for sound insulation requirements between spaces. To help you better understand the sound level requirements of Part E, we have collated an easy to follow table – shown below.

Table 1a: Dwelling-houses and flats – performance standards for separating walls, separating floors, and stairs that have a separating function.
Airborne sound insulation
DnT,w+Ctr dB
(Minimum Values)
Impact sound insulation
L’nT,w dB
(Maximum Values)
Purpose built
Floors and Stairs


Material change of use
Floors and Stairs



Whatever the problem we can usually find an acoustic solution that will satisfy Part E of Building Regulations. If you have a project that’s needs acoustic design advice or needs sound testing then please contact us at: [email protected] or phone us directly on 0203 669 2650 and we should be able to offer you an expedient acoustic solution to help you achieve practical completion.