Gross floor area

Gross floor area is the construction-side measure of a building's size: floor plates measured to the exterior walls, summed across stories, without the Zoning Resolution's carve-outs. It is the number architects, contractors, and appraisers naturally produce — and it differs, sometimes substantially, from zoning floor area, which excludes qualifying cellar, mechanical, and parking space under § 12-10's definitions.

The gap between the measures is a standing source of error: marketed square footage, gross construction area, and zoning floor area describe the same building with different numbers, each legitimate for its purpose. Development math that multiplies FAR against gross-area intuitions — or checks recorded floor area against marketing figures — is comparing currencies without converting.