The Law
The wildlife and countryside act 1981 states that an authorised person can remove nests and eggs of herring gulls (seagulls) and greater black back gulls from a property to preserve public health and safety.
Therefore, there are two main factors regarding the legality of seagull proofing;
Health Risk - As discussed on the health page, all seagulls are a risk.
Authorised Person - This can be your local builder or roofing contractor provided they are working with the property owner's consent.
See the download section for more information regarding the law.