1.1 This section provides guidance on an appropriate programme of sound insulation testing for a sample of properties, under Regulation 20A of the Building Regulations and Regulation 12A of the Approved Inspectors Regulations.
1.2 Sound insulation testing to demonstrate compliance with Requirement E1 should be carried out on site as part of the construction process, and in this Approved Document it is referred to as pre-completion testing. Under Regulation 20A and Regulation 12A, 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. Therefore, the guidance in this section is addressed in the first place to persons carrying out the work (and to testing bodies employed by them). However, it is also addressed to building control bodies, as the Secretary of State expects building control bodies to determine, for each relevant development, the properties selected for testing.
1.3 Testing should be carried out for:
1.4 The normal programme of testing is described in paragraphs 1.29 to 1.31.
1.5 The testing procedure formally approved by the Secretary of State is described in Annex B: Procedures for sound insulation testing.
1.6 The performance standards that should be demonstrated by pre-completion testing are set out in Section 0: Performance - Tables 1 a and 1 b. The sound insulation values in these tables have a built-in allowance for measurement uncertainty, so if any test shows one of these values not to have been achieved by any margin, the test has been failed.
1.7 The person carrying out the building work should ensure that the guidance on construction given in this Approved Document, or in another suitable source, is followed properly to minimize the chances of a failed test. Where additional guidance is required, specialist advice on the building design should be sought at an early stage.
1.8 Testing should not be carried out between living spaces, corridors, stairwells or hallways.
1.9 Tests should be carried out between rooms or spaces that share a common area of separating wall or separating floor.
1.10 Tests should be carried out once the dwelling-houses, flats or rooms for residential purposes either side of a separating element are essentially complete, except for decoration. Impact sound insulation tests should be carried out without a soft covering (e.g. carpet, foam backed vinyl etc) on the floor. For exceptions and further information on floor coverings and testing see Annex B: paragraphs B2.13 and B2.14.
1.11 The results of tests only apply to the particular constructions tested but are indicative of the performance of others of the same type in the same development. Therefore, in order for meaningful inferences to be made from tests, it is essential that developments are considered as a number of notional groups, with the same construction type within each group.
1.12 Grouping should be carried out according to the following criteria. Dwelling-houses (including bungalows), flats and rooms for residential purposes should be considered as three separate groups. In addition, if significant differences in construction type occur within any of these groups, sub-groups should be established accordingly.
1.13 The following guidance should allow suitable sub-grouping in most circumstances.
1.14 For dwelling-houses (including bungalows), sub-grouping should be by type of separating wall. For flats, sub-grouping should be by type of separating floor and type of separating wall. Rooms for residential purposes should be grouped using similar principles.
1.15 The construction of flanking elements (e.g. walls, floors, cavities) and their junctions are also important. Where there are significant differences between flanking details, further sub-grouping will be necessary.
1.16 Sub-grouping may not be necessary for dwelling-houses, flats and rooms for residential purposes that have the same separating wall and/or separating floor construction, with the same associated flanking construction(s), and where the room dimensions and layouts are broadly similar.
1.17 Some dwelling-houses, flats or rooms for residential purposes may be considered to have unfavourable features: an example could be flats with large areas of flanking wall without a window at the gable end. It would be inappropriate for these to be included as part of a group and these should form their own sub-group(s).
Resistance to the passage of sound 12