Useful Definitions

Core Factor: The percentage of common areas in a building (restrooms, hallways) that, when added to the net usable square footage equals the net rentable square footage. May be computed for a building or a floor of a building. A "Loss Factor" or "Load Factor" is calculated by dividing the rentable square footage by the usable square footage

Gross Building Area: The total floor area in an office building measured in square feet or square meters that is associated with that building's use as office building. The area extends to the outer surface of exterior walls and windows and includes office area, retail area, and other rentable areas such as vending machine space and storage area, but excludes parking and roof space

Rentable Square Feet: Usable square feet plus a percentage (the core factor) of the common areas on the floor, including hallways, bathrooms, telephone closets and sometimes main lobbies. Rentable square footage is the number of square feet on which a tenant's rent is based.

Rentable/Usable Ratio: The number resulting from dividing the Total Rentable Area in a building by the Usable Area. The inverse of this ratio describes the proportion of space that an occupant can expect to utilize

Net Rentable Area: Floor area of a building less any vertical penetrations of the floors. No deductions are made for necessary columns and projections of the building.

Circulation Space
Corridors, aisles and other similar space required for occupants to access means of egress and all other functions in and serving their space. Circulation may be classified as either primary, secondary or tertiary, and it may be fully enclosed as in a corridor, or unenclosed,