The total area for which rent is paid. It includes the space actually occupied by the tenant, as well as a pro-rata allocation for common areas such as public corridors, building lobbies, core areas, and restrooms.
The (square footage) for which rent can be charged. Generally it is the gross area of the full floor less the area of all vertical penetrations (elevator shafts, stairwells, mechanical shafts etc.) Rentable area can be measured in many ways, but the most common measurement for office buildings is according to Boma Standards.
Computed by measuring to the inside finished surface of the permanent outer building wall, excluding any major vertical penetrations of the floor. The areas of columns and building projections are included in rentable area. Excluded from rentable area are exterior walls, major vertical penetrations and interior parking spaces.