Party wall (or parti-wall) is a dividing partition between two adjoining buildings (or units) that is shared by the tenants of each residence or business. The wall is sometimes constructed over the center of the property line dividing two terraced flats or row houses so that one half of the wall is on each property. They are sometimes two abutting walls built at different times.

Party walls are typically made of non-combustible material. Where required by code, the party wall could be a fire wall. The wall starts at the foundation and continues up to a parapet, creating two separate and structurally independent buildings on either side. The term can be also used to describe a division between separate units within a multi-unit apartment complex. Very often the wall in this case is non-structural but designed to meet established criteria for sound and/or fire protection between residential units.

This building term which, in England, apart from special statutory definitions, may be used in four different legal senses. Less commonly, it may also be spelled Parti Wall.

It may mean:

1. a wall of which the adjoining owners are tenants in common;
2. a wall divided longitudinally into two strips, one belonging to each of the neighbouring owners;
3. a wall which belongs entirely to one of the adjoining owners, but is subject to an easement or right in the other to have it maintained as a dividing wall between the two tenements;
4. a wall divided longitudinally into two moieties, each moiety being subject to a cross easement, in favour of the owner of the other moiety.

In the United Kingdom, the legal rights and obligations governing work to or adjacent to a Party wall are governed by the Party Wall, etc. Act, 1996 and Party Wall Surveyors specialise in managing the negotiation process between adjoining owners and resolving disputes.

In the USA, the term most commonly refers to the wall within a condominium complex that separates two neighboring units.

Case Law

Andreae v Selfridge & Co. (1938) Dean v Walker (1996) Phips v Pears (1964) Selby v Whitbread (1917)

See also

• Rights of Light
• Architectural acoustics
• Property law

References and external links

• Party wall guidance Royal Institution of Chartered Surveyors (RICS)
• The Party Wall Casebook
• GIA - London based Party Wall and Rights of Light Consultancy
• Party Wall Specialists
• The Party Wall Blog
• Party Wall and Rights to Light Forum