Web Document Noise impact assessment 2013-04-20 - Southwark ...

Camberwell Library21 March 20137/ Internal Acoustic Separation7. Internal Acoustic Separation7.1 Walls7.1.1 The objective of the performance standards required by Section 1.1.2 of BB93; Airborne SoundInsulation between Spaces, is to attenuate airborne sound transmitted between spaces throughwalls and floors.7.1.2 It should be noted that the scope of BB93 applies where partitions separate teaching and studyspaces either from each other, or from ancillary spaces. BB93 does provide criteria for partitionsseparating ancillary spaces (e.g. office to office).7.1.3 In this instance, the above criteria for ancillary spaces will be used on the basis that thepartitions in the proposed scheme are limited to office type spaces.7.1.4 On this basis, we recommend that partitions that achieve a minimum airborne sound insulationof R W 45dB are used between the offices. This will result in speech privacy levels thatcorrespond to a subjective impression of “Normal voices are audible but unintelligible most ofthe time. Raised voices are partially intelligible.”7.2 Floors7.2.1 In the proposed scheme, no significantly noise sensitive areas are indicated on the floor plans.However, if the ground floor was to be used for noise sensitive activities, it would berecommended that some form of impact sound insulation is provided. Airborne sound insulationwithin the space is less of a concern since there are no high noise-generating areas within thespace.7.2.2 Typically, the resilient layer can be incorporated within the floor finish. In this case, any floorfinish is recommended to have a resilient backing with minimum uncompressed thickness of4.5mm or minimum impact sound reduction of ΔL w 17 dB. Carpet typically achieves this, butvinyl finishes will require the additional resilient backing.9