In this Q&A it has been assumed that the leaseholder is entitled or has consent to undertake the works to the structural wall under the terms of the lease. For further information, see Alterations and improvements for property disputes lawyers—overview. Where lands of different owners adjoin and, at the line of junction: • those lands are built on, or • a boundary wall, being a party fence wall or the external wall of a building, has been erected A building owner has the right to undertake various types of repairs to the party wall under section 2 of the Party Wall etc Act 1996 (PWA 1996). Under PWA 1996, s 20, a party structure is a party wall or a floor partition