HEA 05

Applying internal partition sound insulation criteria to internal doors - KBCN0665

Where sound insulation criteria apply to internal partitions the calculations do need to include any doors which are part of the wall in question. While sound insulation performance of a typical door will be lower than for a typical wall, with careful design, specification and detailing, this can be overcome. 

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International suitably qualified professionals - KBCN1266

In some issues the International NC and RFO schemes prescribe specific requirements for suitably qualified professionals. We appreciate that some countries might have different recognition schemes in place, and these might differ from the BREEAM requirements. Where this is the case, assessors should submit a technical query with appropriate information, and we will review and approve each situation on a country basis.

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Prerequisite – users with special hearing and communication needs - KBCN0969

Intent Criterion 1c ensures that the suitably qualified acoustician has influenced the design of the asset to:

• Meet the acoustic requirements of users with special hearing and communication needs.
• Ensure that accessible acoustic design is considered where this is not adequately covered by local legislation.

What this should cover will depend on the asset type and expected users. Asset users The UK Department for Education document BB93 Acoustic design of schools: performance standards building bulletin 93 (February 2015) defines users with special hearing or communication needs as those with any of the following:

• Speech, language and communication difficulties.
• Visual impairments.
• Fluctuating hearing impairments caused by conductive hearing loss.
• Attention deficit hyperactivity disorder (ADHD).
• An auditory processing disorder or difficulty.
• Being on the autistic spectrum.

This list is not exhaustive, and the suitably qualified acoustician must consider typical asset users, along with the other points a-d when giving early design advice regarding room layout, sound insulation and reverberation times. Accessibility features The principles of accessible design are universal and could be applied in a wide range of assets. Additional features that could be relevant to accessible acoustic design include, but are not limited to:

• Designation of quiet zones.
• Hearing assistive technologies.
• Induction loop systems.
• White noise machines.
• Infrared and FM systems to provide direct audio to individuals with special hearing needs.
• Noise barriers.

The suitably qualified acoustician must use their professional judgement to determine the scope of any such features as part of the design. Where no features are applicable this must be clearly justified.

04-Sep-2024: Wording and intent clarified. Information on additional accessibility features added. Scheme applicability updated. Title updated.
01-Mar-2019: Amended to clarify that this is a 'typical' list of users, but does not impose a new requirement.

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Remedial works – timing of acoustic re-testing - KBCN1164

The intent of CN "Remedial works" is that, where these are required, re-testing is carried out prior to handover and occupation. However, it is permissible to carry out the re-testing post-occupation. This is provided any specific guidance for particular building types related test conditions have been met (for instance, it may be that some building specific guidance requires furniture or carpets to not be present during the testing). Compliance cannot be achieved based on a letter from the SQA confirming that the contractor has followed their advice to achieve the required performance.

07.11.18 KBCN amended to allow for re-testing to be carried-out post-handover.

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