GFA
Abbreviation for gross floor area. Generally, the gross floor area is the sum of the floor areas of the spaces within the building, including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft (2.2 meters) or greater. Measurements must be taken from the exterior faces of exterior walls OR from the centerline of walls separating buildings, OR (for LEED ID+C projects ) from the centerline of walls separating spaces. Excludes non-enclosed (or non-enclosable) roofed-over areas, such as exterior covered walkways, porches, terraces or steps, roof overhangs, and similar features. Excludes air shafts, pipe trenches, chimneys and floor area dedicated to the parking and circulation of motor vehicles
(Architecture Dictionary, 2023)