I’m looking for information on selling some or all of a rowhouse back yard to a neighbor (i.e., so the buying neighbor ends up with a double-width yard and a sort of L-shaped lot, while the selling neighbor ends up with a smaller yard or no yard at all). Are there any tricky legal issues? How did you deal with air rights/FAR? What is a fair price for half of a backyard? For all of a backyard? Assume that there is no landscaping to speak of and both yards are basically blank slates.