Common Party Wall Rights
Rights in party walls, of course, can arise under an agreement between the adjoining landowners. But if they do not write their agreement down, will the law imply one? Yes. In R. Powell & P. Rohan, 3The Law of Property, Matthew Bender (1992), §61.03 the general rights of adjoining landowners regarding party walls were there is no written agreement is discussed.
A party wall relationship may also be created by less formal transactions. The relationship comes into existence, for example, where A and B are adjacent owners and orally agree that A will construct a wall and that B will contribute to its costs, and this oral agreement has been implemented by both parties. Moreover, the locally operative presumption as to the nature of the relationship becomes applicable in the absence of a specific agreement on the point. Similarly, a party wall relationship arises where A, who has a building on his lot, either gives B oral permission or fails to object to B attaching his structure to A's wall, and B acts in reliance upon A's word or conduct by spending money or labor on the project. The part performance eliminates the applicability of the Statute of Frauds. However, before the parties have acted on an oral agreement so that it becomes enforceable, it is a mere license that can be revoked by either party.
Also, specifically with respect to Massachusetts law, Union National Bank v Nesmith 238 Mass. 247, 130 N.E. 251 stands for the proposition that a party wall right contemplates reciprocal rights of support with respect to the common wall, the rule being an extension of the common law right of natural support.
Without a written party wall agreement, however, the destruction of the building(s) will cause the reciprocal rights to become extinguished, as there is no property on which the implied rights can operate and there is no agreement to extend their effect to new structures. See Union National Bank, above.
A right that in a way is related to party wall rights is an easement for light and air. However, here the law will not imply such a right. An easement for light and air must be specifically granted.