Owners of adjoining properties, especially in cities, frequently find it advisable and advantageous to enter into arrangements whereby their buildings shall be supported by a common wall. These arrangements are ordinarily evidenced by party-wall agreements or covenants, so-called, out of which have grown a number of interesting questions. It not infrequently happens that when one owner desires to build such a wall his neighbor, for one reason or another, is not ready to join in the undertaking, so an agreement is entered into between the two adjoining owners whereby one agrees to proceed with the erection of the wall at his own expense, the other granting the right to rest the wall one-half on his lot and agreeing to pay one-half the cost or value thereof when he makes use of it. The details of these agreements may vary almost without limit, but the main features are usually substantially as stated. Quite frequently the parties desire the benefits and burdens of the agreement to pass to and be binding upon future owners of the lots of the contracting parties, and the agreements are then entered into not only on behalf of the parties themselves, but their heirs and assigns are expressed as being bound, and frequently there is also a further clause that the agreements or covenants shall be construed as covenants running with the properties of the respective parties. So long as the original contracting parties remain the owners of their respective lots, not much question can arise as to who is obligated to pay or who is entitled to receive such payment when the wall is made use of. It is when one or both of the lots are sold that very serious and troublesome questions arise along these lines, and there has been a lamentable lack of harmony in the decisions. Although many of the seemingly inconsistent conclusions may be explained on the basis of the wording of the contracts or the peculiar facts of the cases, there is clearly a diversity of view on the fundamental legal principles involved.
Aigler, Ralph W. "The Running with the Land of Agreements to Pay for a Portion of the Cost of Party Walls." Mich. L. Rev. 10 (1912): 187-211.