Party wall

A party wall (occasionally parti-wall or parting wall, also known as common wall) is a dividing partition between two adjoining buildings (or units) that is shared by the tenants of each residence or business. When built for this purpose, the builder will lay the wall along a property line dividing two terraced flats or row houses, so that one half of the wall's thickness lies on each property. This type of wall is usually structural. Party walls can also be formed by two abutting walls built at different times. 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.

Party walls are typically made of non-combustible material. Where required by code, the party wall could be a firewall. The wall starts at the foundation and continues up to a parapet, creating two separate and structurally independent buildings on either side.

While party walls are effectively in common ownership of two or more immediately adjacent owners, there are various possibilities for legal ownership: the wall may belong to both tenants (in common), to one tenant or the other, or partly to one, partly to the other. In cases where the ownership is not shared, both parties have use of the wall, if not ownership. Other party structures can exist, such as floors dividing flats or apartments.

Apart from special statutory definitions, the term "Party Wall" may be used in four different legal senses.

In English law the party wall does not confirm a boundary at its median point and there are instances where the legal boundary between adjoining lands actually comes at one face or the other of a wall or part of it, and sometimes at some odd measurement within the thickness of the wall. The legal position is, however, clear insofar as a party using or benefiting from a party wall or structure abutting, on or in its land has rights to use the wall and for it to be retained should the other side no longer wish it to be there. For this reason, expert surveyors are used in the main to issue notices, deal with the response from someone receiving a notice and settling any dispute by an Award. Details can be obtained from the Royal Institution of Chartered Surveyors.

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