Michael Stern

By Michael Stern, JDS Development Group Photo by Bekky Bekks on Unsplash On most assembled sites in New York City there is a masonry wall standing directly on a lot line, shared by two buildings that were never designed together. It is the oldest structure on the property and it is usually the only one still standing when the new building opens. This is for the developers, architects and structural engineers who are looking at a site like that and working out how much of it they actually control. A party wall is inherited structure. Everything the new building does along that edge gets arranged around masonry that was built for another purpose, by people who are gone, to a standard nobody wrote down. A Party Wall Straddles the Lot Line A party wall sits astride the boundary rather than beside it, with part of its thickness on each lot. Both buildings bear on it, which is what distinguishes it from a wall that merely stands close to the line. Two independent walls built tight agai...

By Michael Stern, JDS Development Group Photo by Parsoa Khorsand on Unsplash An owner of a five story building on a good block asks what it would take to add three floors, and the answer comes back from the title report rather than from the zoning map. The lot still has a district, a permitted floor area, and a shape. What it no longer has is the unused area that once sat above the roof, because that area was sent to a neighboring lot years ago and it is not coming back. This is written for developers looking at assemblage, for land use lawyers who field the same question from the other direction, and for owners of small buildings who assume the room above them is still an asset they hold. The mechanism is ordinary. The consequence is permanent, and that combination is rare enough in this business to be worth understanding before anyone signs anything. How Floor Area Leaves a Lot Permanently Unused floor area is an arithmetic difference. It is what the zoning permits on a lot les...

By Michael Stern, JDS Development Group Photo by camera obscura on Unsplash A lot on an assembled site can carry floor area that no survey of that lot will ever show. The area arrived from a neighbor, it lives in an instrument filed with the office that keeps the land records, and the only place it can be proved is the record of title. This is written for developers, land use lawyers and underwriting professionals who have to establish how much building a site actually holds before a design exists. On the sites I work on the buildable envelope is assembled rather than found, and the assembly is legal before it is physical. The document that performs it is a recorded declaration, and everything the tower is permitted to be rests on that document being drafted and filed correctly. What a Development Rights Transfer Actually Records A transfer of unused floor area is not a conveyance of land. Nothing about the boundary of either lot changes and both owners keep their parcels. W...

By Michael Stern, JDS Development Group Photo by Sebastian Hages on Unsplash Two lots on the same block each hold floor area they will never use, and a third lot sits between them. That third lot decides whether either of the first two can ever contribute to a tower, because under the general rule floor area moves only between lots that form a single zoning lot, and a zoning lot has to be contiguous. This is written for developers and land use professionals evaluating an assemblage, and for anyone who has looked at a block map and wondered why a small site can hold a tall building while a larger one nearby cannot. What a zoning lot is and why it is the unit that matters Floor area is counted on the zoning lot, a unit the zoning creates for its own purposes, which can be one tax lot or several tax lots treated as one under the rules. The deed map and the zoning map therefore disagree by design. The deed map shows who owns what, the zoning map shows what may be built where, and the ...