Identification

• A party wall agreement accompanies the deed when the property is sold, becoming part of the title. The document defines the ownership rights and responsibilities of the respective properties joined by the party wall. It lists specific legal remedies for default by either side. Owners may renegotiate the agreement by mutual consent, so long as the new agreement meets local codes and zoning ordinances.
  
  

Benefits

• The party wall agreement allows owners to build to the common boundary line rather than using part of the lot for setbacks. Using a design that incorporates a party wall often allows construction on lots that might otherwise be unbuildable because of limited width. A true structural party wall offers superior insulation and soundproofing between the units to increase privacy.
  
  

Function

• A structural party wall offers noise dampening benefits, as well as support to a building. Built more as two walls that happen to touch, a structural party wall contains additional air space and insulation to reduce sound transmission. Designers avoid providing a conduit for sound between the two sides by positioning utility structures such as electrical outlets in different locations rather than back-to-back.
  
  

Considerations

• Not all common walls are party walls in the structural sense. Ask to see specifications or blueprints for any property under consideration. Look for double sets of studs and description of the wall material. Thicker wallboard or double-layered wallboard will provide better sound-dampening than a single thin layer. Additional soundproofing materials may be incorporated in the wall to reduce sound transmission.
  
  

Warning

• The most carefully built party wall cannot compensate for a bad neighbor. Do not rely on the presence of a party wall to provide a peaceful residence. Evaluate the neighborhood and particularly the adjoining neighbor before making a purchase offer. Visit the unit when the neighbors are home to check for noise levels that exceed the wall's ability to muffle or are generated outside the home, such as in the backyard. A party wall has no effect on such sources of noise.