REBNY

To determine the usable area of below grade, cellar and sub-cellar areas, follow the same procedures as are appropriate for single or multiple tenant floors except that the following additional areas should be deducted from usable area: -Machine rooms and pump rooms and their enclosing walls. -Electric switchgear rooms and their enclosing walls. -Telephone equipment rooms and their enclosing walls. -All space devoted to servicing the operation of the building, i.e., cleaning contractors, storage, building maintenance shop, building engineer’s office, etc.

A term used in the REBNY Standard to describe the usable area available to a tenant on a multi-tenant floor, excluding corridors.

1. The rentable area of a store shall be computed by measuring from the building line in the case of street frontages, and from the inside surface of the outer building walls to the finished surface of the corridor side of the corridor partition and from the center of the partitions that separate the premises from adjoining rentable area.
2. No deductions shall be made for columns and the projections necessary to the building.
3. Rentable area of a store shall include all area within the outside walls, less the following, with their enclosing walls, if serving more than on tenant: building stairs, fire towers, elevator shafts, flues, vents, stacks, pipe shafts and vertical ducts.
4. The following area shall be included in rentable area, if such areas exclusively serve a store, together with their enclosing walls: private stairs, private elevators, toilets, air conditioning facilities, janitor’s closets, slop sinks, electrical closets and telephone closets. When air conditioning facilities serve more than one tenant area, they shall be apportioned in the same manner as that used for single tenancy floors.
5. Where a store fronts on a plaza or arcade which is intended for use by the general public and is not for the exclusive use of the store tenant, its customers, etc., the area of the plaza or arcade shall not be included in determining the rentable area off the store.

Because of dissimilarities among buildings, calculations of rentable area may vary. If requested, owners should disclose to prospective tenants the loss factor used for spaces under consideration.

First, calculate the usable area as if for a single tenant floor. Then deduct corridor areas, including toilets, supply room, etc., but do not deduct the enclosing walls of such corridor. Measure the net usable area of each space on the floor by measuring each enclosing wall which is a building exterior wall to the outside surface of the exterior wall, or to the outside surface of the glass as the case may be. Measure demising wall to the center and walls which about corridors to the corridor side of the finished surface of the corridor wall. To determine the usable area on a multiple tenant floor, apportion the corridor area to each space by multiplying the corridor area by a fraction, whose numerator is the net usable area of the space and whose denominator is the total of the net usable areas of all the spaces on the floor, and add the result to the net usable area of the space. 

Measure the floor to the outside surface of the building. Subtract from this area the following, including the finished enclosed walls: -Public elevator shafts and elevator machines and their enclosing walls. -Heating, ventilating, and air-conditioning facilities (including pipes, ducts and shafts) and their enclosing walls, unless such equipment, mechanical room space, or shafts serve the floor in question. -Fire towers and fire tower courts and their enclosing walls. -Main telephone equipment rooms and main electric switchgear rooms, except that telephone equipment, and electric switchgear rooms serving the floor exclusively shall not be subtracted.