Robust Details and Sound Testing
The current edition of Approved Document E which came into force on 1 July 2003 introduced pre-completion testing for sound insulation as a means of demonstrating compliance. Pre-completion testing has applied to rooms for residential purposes, houses and flats formed by conversion of other buildings since 1 July 2003, and applied to new houses and flats since 1 July 2004. Also, from 1 July 2004, the use of robust details in new houses and flats was accepted as an alternative to testing.
Robust details are high performance separating wall and floor constructions (with associated construction details) that are sufficiently reliable not to need the check provided by pre-completion testing.
Design details approved by Robust Details Ltd
Robust Details Ltd is a non-profit distributing company, limited by guarantee, set up by the house-building industry. Its objectives are broadly to identify, arrange testing and, if satisfied, approve and publish design details that, if correctly implemented in separating structures, should achieve compliance with Requirement E1 (Protection against sound from other parts of the building and adjoining buildings). They also carry out checks on the performance achieved in practise.
The robust design details are available in a handbook, which may be purchased from Robust Details Ltd. Further details are available on their website at www.robustdetails.com
Although the design details are in the public domain, their use in building work is not authorised unless the builder has registered the particular use of the relevant design details with Robust Details Ltd and obtained unique numbers from the company. Each unique number identifies a house or flat in which one or more of the design details are being used.
The system of unique numbers make possible an essential part of Robust Details Ltd's procedures for ensuring that design details it has approved deliver reasonable sound insulation performance in practise. Robust Details Ltd carry out a programme of checks on a proportion of cases where approved design details are used.
Under the regulations the requirement for sound testing does not apply to parts of the building which are covered by approved Robust Details, where all the following apply:
- the building work consists of the erection of a new dwelling-house (for example: a semi-detached or terraced house) or a building containing flats;
- the person carrying out the building work notifies Building Control before the start of building work on site that, in specified parts of the building where using one or more specified design details from those approved by Robust Details Ltd. The notification must be given no later than the date on which notice of commencement of construction is given to building control;
- the notification specifies the unique number or numbers issued by Robust Details Ltd in respect of the specified use of the design detail or details;
- the building work carried out in respect of the part or parts of the building identified in the notification is in accordance with the design detail or details specified in the notification.
If the notification is late, or if it does not specify the relevant parts, the design details in question and the unique number or numbers, the parts of the building in question are subject to sound testing under Regulation 41 in the usual way.
If the notification is itself valid but the work is not carried out in accordance with the design details, the relevant separating structures become subject to sound testing. It would be open to the builder to take remedial action such that Building Control was satisfied that the work has been brought into compliance with the specified details. With that exception, testing under Regulation 41 would be needed on all structures that have been subject to a valid notification under Regulation 41(4) but which in the opinion of Building Control have not then been constructed in accordance with the specified details.
Sound insulation testing
Sound insulation testing to demonstrate compliance should be carried out on site as part of the construction process, and in Approved Document E it is referred to as pre-completion testing. Under Regulation 41, the duty of ensuring that appropriate sound insulation testing is carried out falls on the person carrying out the building work, who is also responsible for the cost of the testing.
Testing should be carried out for:
- purpose built dwelling-houses and flats;
- dwelling-houses and flats formed by material change of use;
- purpose built rooms for residential purposes;
- rooms for residential purposes formed by material change of use.
The person arranging for the sound insulation testing to be carried out, should make sure that the tests are carried out by a test body with appropriate third party accreditation. Testing bodies currently approved to conduct these tests should have United Kingdom Accreditation Service (UKAS) accreditation or be members of the Association of Noise Consultants (ANC) Registration Scheme.
Regulation 41 (Sound insulation testing)
(1) Subject to paragraph (4) below, this regulation applies to -
(a) building work in relation to which paragraph E1 of schedule 1 imposes a requirement; and
(b) work which is required to be carried out to a building to ensure that it complies with paragraph E1 of Schedule 1 by virtue of regulation 6(1)(f) or 6(2)(b).
(2) Where this Regulation applies, the person carrying out the work shall, for the purpose of ensuring compliance with paragraph E1 of Schedule 1 -
(a) ensure that appropriate sound insulation testing is carried out in accordance with a procedure approved by the Secretary of State; and
(b) give a copy of the results of the testing referred to in sub-paragraph (a) to the local authority.
(3) The results of testing referred to in paragraph (2)(a) shall be -
(a) recorded in a manner approved by the Secretary of State; and
(b) given to the local authority in accordance with a paragraph (2)(b) not later than the date on which the notice required by regulation 16(4) is given.
(4) Where building work consists of the erection of a dwelling-house or a building containing flats, this regulation does not apply to any part of the building in relation to which the person carrying out the building work notifies the local authority, not later than the date on which he gives notice of commencement of the work under regulation 16(1), that for the purpose of achieving compliance of the work with paragraph E1 of Schedule 1, he is using one or more design details approved by Robust Details Limited, provided that -
(a) the notification specifies -
(i) the part or parts of the building in respect of which he is using the design detail;
(ii) the design detail concerned; and
(iii) the unique number issued by Robust Details Limited in respect of the specified use of that design detail; and
(b) the building work carried out in respect of the part or parts of the building identified in the notification is in accordance with the design detail specified in the notification.