2.1 KiB
id, aliases, title, tags
| id | aliases | title | tags | |||||
|---|---|---|---|---|---|---|---|---|
| Building Area Classification |
|
Building Area Classification
- G = Gross Area
- R = Rentable Area
- U = Usable Area
- N = Net Area
G > R > U > N
Gross Area (GSF)
Gross Area is the total floor area of a building.
Whether the area includes exterior wall area depends on the relevant standard.
-
International Building Code (IBC): measured to the interior face of exterior walls.
-
Building Owners and Managers Association (BOMA): total footprint, including exterior wall thickness.
Rentable Area (RSF)
Rentable Area includes tenant exclusive space (usable area) plus a pro-rata share of common areas (load factor).
\text{Rentable Area} = \text{Usable Area} \times (1 + \text{Load Factor})
Usable Area (USF)
Usable Area is the tenant's exclusive space. the area physically occupied and controlled by a specific tenant.
Usable Area includes:
- Primary functional areas (offices, workstations, meeting rooms)
- Internal circulation within the tenant's space
- Columns, recesses, and other features within the leased boundary
But excludes:
- Common corridors and lobbies
- Shared service areas
- Major vertical penetrations (elevator shafts, stairs)
Net Area (NSF)
the actual functional, programmable space.
Also called Net Assignable Area.
Net Area includes:
- Actual functional program spaces (offices, classrooms, apartments)
- Space planned for specific uses in a program
But it excludes:
- All circulation (even within tenant space)
- All service and support spaces
- Structural elements, wall thicknesses
Building Efficiency
Building efficiency is the ratio of usable or rentable area to gross area. This denotes what percentage of the building is functionally usable.
\text{Building Efficiency} = \frac{ \text{Net Assignable Area} }{ \text{Gross Area} }
A higher percentage means less area is lost to structure, mechanical spaces, or circulation.
- Office buildings: 75-90%
- Residential buildings: 80%+
- Hospitals and laboratories: 50-65%