Finished Surface - A wall, ceiling or floor surface, including glass, as prepared for tenant use, excluding the thickness of any special surfacing materials such as panelling, furring strips and/or carpet.

Dominant Portion - The portion of the inside finished surface of the permanent outer building wall which is 50% or more of the vertical floor-to-ceiling dimension. For example, if a window is more than 50% of the wall height, then the inside of the glass is the Dominant Portion. If not, then the inside finished surface of the wall is Dominant. 

Gross Building Area - The total constructed area of a building, as measured to the exterior of all outside walls. ie the building footprint. It is generally not used for leasing purposes.

Gross Measured Area - The total area of a building enclosed by the Dominant Portion, excluding all parking areas and loading docks (or portions of same) outside the building line. Basically, equals the sum of Floor Rentable + vertical penetrations . Generally not used for leasing purposes, and is calculated on a floor by floor basis.

Major Vertical Penetrations - Stairs, elevator shafts, flues, pipe shafts, vertical ducts and the like, and their enclosing walls. Atria, lightwells and similar penetrations above the finished floor are included in this definition. Not included, however, are vertical penetrations built for the private use of a tenant occupying office areas on more than one floor. Structural columns, openings for vertical electric cable or telephone lines, and plumbing chases, are not considered as major vertical penetrations.

Floor Rentable Area - Equals the Gross Measured Area of a floor less the major vertical penetrations for that same floor. Generally fixed for the life of a building, and is rarely affected by changes in corridor size or configuration, as all such corridors are included in the Floor Rentable.

Usable Area - The measured area of an Office area, Store Area, or Building Common Area, on a floor. The total of all usable areas on a floor equals the Floor Usable Area of that same floor.

The Usable area represents the actual occupied area of an office or store area, and is of most importance to a tenant in both their evaluation of a space, and in their allocation of the space to house personnel.

Office Area - The area where a tenant normally houses personnel and/or furniture, for which a measurement is to be computed.

Store Area - The area of an office building suitable for retail occupancy, and included in Floor Usable Area. Store area requires a street frontage and ground level, but does not necessarily require a separate entrance.

Building Common Area - The areas of the building that provide services to building tenants but which are not included in the office area or store area of any specific tenant. Typically included in such areas are main lobbies, atrium spaces at the level of the finished floor, concierge areas, conference rooms, lounges, food service facilities, health or fitness centers, daycare facilities, locker or shower facilities, mail rooms, and service areas such as fully enclosed mechanical or equipment rooms. Parking areas, portions of loading docks outside the building line, and major vertical penetrations are specifically excluded.

Floor Usable Area - The sum of Usable areas, office areas, store areas, and Building common areas on a single floor. This figure can vary over the life of a building, as corridors expand and contract and floors are renovated.

Floor Common Area - The areas on a floor which are available primarily for the use of tenants on that floor. Examples include washrooms, janitorial closets, electrical rooms, telephone rooms, mechanical rooms, elevator lobbies and public hallways.

Floor R/U Ratio - Basically, the sum of total Floor Rentable / total Floor Usable , for a given floor. The resulting ratio is used to convert any Usable Area to a Basic Rentable Area.

Basic Rentable Area - This is the Usable area of an office, store or building common area, plus its share of the floor common areas on that floor. The total of all Basic Rentable areas on a floor equals the Floor Rentable area of that same floor.

It should be noted that under older versions of the BOMA Standard, the Basic Rentable Area was in fact the final Rentable Area, as previous versions worked on a floor-by-floor basis only.

Building Rentable Area - Equals the sum of all the Floor Rentable areas.

Building R/U Ratio - This ratio represents the gross-up factor to be applied in distributing Building Common Area over all Usable Areas in a building.

Rentable Area - This is the Usable area of an office or store area, with its associated share of both Floor common area and Building common area added on. Rentable area is determined by multiplying the Usable area by the combined R/U ratio .

R/U Ratio - The combined conversion factor, obtained by multiplying the Floor R/U by the Building R/U ratios, which when applied to any Usable area, gives the Rentable area of that office or store area.   In our Building Report, we refer to it as the "Combined R/U" to clearly differentiate it from the other component R/U factors.

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