Party Wall

DEFINITION of 'Party Wall'

In real estate, a shared wall that separates housing units. Party walls are most commonly found in apartments, condominiums and office complexes where different tenants share a common structure. Party walls can be a non-structural wall, but laws in various jurisdictions outline requirements for how party walls must be constructed.


Party walls are sometimes built with additional insulation so that sound from an adjoining unit does not disturb neighbors. In addition, some building codes require party walls to be built as fire walls, with noncombustible material extending from the foundation to the roof. If a fire occurs in one unit, a fire wall helps to slow the spread of the fire into adjoining units. Not only is this safer for tenants, but it also helps to contain fires and limit property damage.