Sound insulation standards
All new habitable rooms need to be insulated to ensure an acceptable noise level (defined in the District Plan as LDN 40 dB) when doors and windows are closed.
If the windows in the room can be opened, you must also provide a source of fresh air that is pumped from outside the house using a mechanical fan.
An acoustic engineer will need to certify that the proposed building or extension is designed to meet these requirements.
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