The minimum requirements depend on a variety of factors such as if the development is a new build or refurbished, whether the development is intended to be a permanent dwelling, or classified as “rooms of residential purposes” (e.g. hotels, student accommodation, etc).
New builds must achieve impact sound test results of no more than 62dB L’nTw and airborne sound insulation of no less than 45dB DnTw+Ctr. Converted properties must achieve impact results of 64dB L’nTw or lower and airborne sound insulation of no less than 43dB DnTw+Ctr.