Noise from neighbours is a common source of annoyance in multifamily buildings. Occasionally the annoyance is so great that one occupant decides to alter the structure to try to reduce the intrusive noise. These pages are meant as a guide for such people. They deal only with sound transmission between adjacent homes and not with reduction of aircraft, traffic or other external noises. In the latter cases, sound enters the home most often through the windows.

Before embarking on any structural changes, it is most important to understand that the sound isolation between two homes is not determined only by the common wall or floor. All the other parts of the construction - side walls, ceilings, floors under walls - can transmit sound. Flanking sound transmission, as this is called, can be very important, to the point that it dominates the combined sound transmission. If this happens, improving the common wall or floor may not significantly change the combined sound isolation.

One tenant acting alone might improve the structure, but co-operation from the neighbour is usually very useful. Although repairs are sometimes minor, extra construction could require some fairly drastic and quite expensive changes.

No construction ever completely stops sound. All that can be done is to reduce the level of the transmitted sound to the point that it no longer disturbs you, the listener, because it is masked by the naturally occurring sound in your own home.

The amount of noise you hear in your home depends on the amount of noise your neighbour makes, the sound-transmitting properties of the building, and the level of background noise present in your own home. All three factors are important. For example:

Steps to improvement