Gross floor area
Gross floor area (GFA) represents the sum of all floor surfaces within a building, calculated from the outer face of the external walls. It includes every horizontal plane between floor and ceiling, regardless of function or occupancy status.
- Structural elements (walls, columns, cores)
- All circulation spaces (corridors, lobbies, stairwells)
- Service areas (lift shafts, mechanical rooms, plant rooms)
- Non-heated spaces (parking, storage, ancillary areas)
GFA serves as the primary metric for rental valuation, operational cost allocation, and building performance benchmarking. It is distinct from usable floor area (UFA), which measures only lettable or occupiable space.
