The Party Wall etc Act 1996 provides a framework for preventing and resolving disputes in relation to party walls, boundary walls and excavations near neighbouring buildings.
Building Owners' proposing to start work covered by the Act must give Adjoining Owners' notice of their intentions in the way set down in the Act. Adjoining Owners' can agree or disagree with what is proposed. Where they disagree, the Act provides a mechanism for resolving disputes.
The Act is separate from obtaining Planning permission or Building Regulations approval. For further information there is some useful guidance on the www.gov.uk website.