parti-wall

party wall, or parti-wall

A wall erected on a property boundary as a common support to structures on both sides, which are under different ownerships. A wall built partly on the land of one owner, and partly on the land of another, for the common benefit of both in supporting the construction of contiguous buildings. A division wall between two adjacent properties belonging to different persons and used for mutual benefit of both parties, but it is not necessary that the wall should stand part upon each of two adjoining lots, and it may stand wholly upon one lot. Soma Realty Co. v. Romeo, 31 Misc.2d 20, 220 N.Y.S.2d 752, 755.

In the primary and most ordinary meaning of the term, a party wall is

(1) a wall of which the two adjoining owners are tenants in common. But it may also mean

(2) a wall divided longitudinally into two strips, one belonging to each of the neighboring 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 (the term is so used in some of the English building acts); or

(4) a wall divided longitudinally into two moieties, each moiety being subject to a cross-easement in favor of the owner of the other moiety