The Party Wall Act 1996 came into force on 1 July 1997 and is largely based on Part VI of the London Building Acts (Amendment) Act 1939.
You must find out whether that work falls within the scope of the Act if you intend to carry out building work which involves:
If the work you intend to carry out does involve the criteria above, you must serve the statutory notice on all those defined by the Act as adjoining owners. (Remember that reaching agreement with adjoining owners on a project that falls within the scope of the Act does not remove the possible need for planning permission or building regulations approval).