Acoustics-Related Credits Under BRE’s New Home Quality Mark Scheme (replacement to Code for Sustainable Homes)
BRE’s new scheme for assessing the quality of new residential developments was released last month. The ‘Home Quality Mark’ (HQM) scheme works similarly to the Code for Sustainable Homes (which was withdrawn last year, but still applies to many active sites) however the HQM scheme is intended to assess the overall quality of new residential development rather than just factors affecting sustainability. For example, the new scheme considers things like the provision of high speed internet and mobile phone network coverage. The full document can be found here.
Importantly, HQM is not compulsory and therefore it is not clear how popular the new scheme will be. However, BRE are confident that developers will adopt the scheme in order to attract potential buyers.
Set out below is a comparison of the available acoustics-related credits under the new scheme versus those in the Code for Sustainable Homes.
|Item||Code for Sustainable Homes (now withdrawn)||Home Quality Mark|
|Sound insulation between separate dwellings (i.e. across party walls and floors)||4 credits available:
||4 credits available:
|Sound insulation between rooms within dwellings (i.e. across internal walls and floors)||No credits available.||4 credits available:
|Internal and external noise levels (e.g. in bedrooms, living rooms and gardens etc)||No credits available.||4 credits available:
It can be seen from the above that acoustic performance is given more weight in the new scheme with the introduction of credits for low internal noise levels and increased sound insulation to internal walls and floors. The credits for increased sound insulation between dwellings remains the same as in the Code for Sustainable Homes.
In terms of demonstrating compliance, onsite testing is still required to claim credits for sound insulation between dwellings, unless suitable Robust Details have been used and registered.
The internal sound insulation credits can be claimed by simply adopting acoustically upgraded constructions at the design stage (there is no requirement for testing).
Post-completion testing will be required to claim the available credits for internal and external noise levels. It would be logical to carry out this testing at the same time as pre-completion sound insulation testing to minimise cost. There will be a few technical challenges associated with claiming these credits:
- The measurement process is ambiguous and arguably will not be very accurate.
- Measurements need to be carried out during the daytime. It is difficult to accurately measure noise levels on active sites during the daytime due to noise from onsite construction work.
- Given the inherent tolerances in acoustic design it will be difficult to ensure that the credits are achieved at noisier sites without including large design margins.
- The available credits for external amenity areas are unlikely to be achievable in urban developments that have balconies.
Given the above points, it will be difficult for developers to rely on achieving the credits for internal and external noise levels in most urban developments that are near to busy roads or railways etc (this is perhaps the intention!).
We hope the above is useful – please let us know if you would like to talk through the acoustic requirements of the Home Quality Mark scheme further.