Your local planners want to see that the noise impact assessment has been included as part of your planning application. One of the many areas which is covered is noise. This is because it can easily be sometimes overlooked. If your planning application is for a new set of residential properties or it is a commercial or industrial application, then the Local Authorities may well ask to see proof that noise will not be a factor. If it will be, then they will want to see that the effect would be lessened.
If your planning application is of an industrial nature (air conditioning etc), then a Noise Impact Assessment would usually be requested as part of the application. The first part of any Noise Impact Assessment should always be to establish the ambient noise levels for the area BEFORE the proposed installation. Calculations would need to be performed to establish the noise outside the closest noise sensitive properties. This level would then be ‘rated’ in accordance to BS4142. The rated level would then be compared to the current noise levels in the area.
If your planning application is for a house (or set of houses) close to a noisy road or railway, then that could also require a Environmental Noise Assessment. Similarly, noise levels would need to be obtained for the current climate. These would help to design appropriate ventilation measures so noise inside would be acceptable. BS8233 and WHO make recommendations about internal noise levels. In a nutshell, noise levels at night time should remain at, or below, 30dB(A) for a well designed house.