It is the Party Wall Agreement.
If the proposed works affect a party wall, e.g. beams to bear onto the party wall, the owners or leaseholders of adjoining properties must be informed. The relevant legislation is the Party Wall etc Act 1996. Guidance notes on the Act are available from ODPM Free Literature, PO Box 236, Wetherby, L23 7NB,or they can be accessed on the internet from the website of the Office of the Deputy Prime Minister (
http://www.safety.odpm.gov.uk (external)). The Local Authority does not have a role in the implementation of the provisions of the Act.