BOMA Office Standards
Standard Method for Measuring Floor Area in Office Buildings
The BOMA 2010 "Office Buildings: Standard Methods of Measurement And Calculating Rentable Area", is the latest publication from BOMA to facilitate and standardize the determination of usable and rentable areas in commercial office buildings. Like the BOMA 1996 Standard, the BOMA 2010 Standard measures buildings on a building-wide basis and therefore it is necessary to have complete building CAD data in order to determine rentable areas. The new BOMA 2010 standard introduces many new concepts and definitions and it also renames well known industry terms. For example, Floor Common Area is now known as Floor Service and Amenity Areas and Tenant Usable Area is now Occupant Area. Another notable difference is the exclusion of a Gross Building Area (or Construction Area) calculation. Instead, BOMA has developed a separate standard for Gross Building Areas titled "The Gross Areas of a Building: Methods of Measurement". The biggest change however is that BOMA 2010 provides the option of selecting two distinct measuring methods; each of which will yield significantly different results. The two methods are known as Method A (Legacy Method) and Method B (Single Load Factor Method), summarized below. Furthermore, if you don't like the results of either method, BOMA allows real estate professionals the option of applying their own Capped Load Factor which is not to exceed the Load Factor(s) determined by Method A and/or Method B.
Method A (Legacy Method) calculates areas similarly to the BOMA 1996 ANSI/BOMA Z65.1-1996 Standard. An inherent conceptual weakness of BOMA 1996 is that like Tenant Usable Areas, Floor Common Area is applied to all Building Common Areas, but many Building Common Areas (although necessary to the operation of the building) are not directly used by tenants and therefore should not be grossed-up by Floor Common Area. For example, it has been questioned as to why a building mechanical room (Building Common Area) proportionately shares the washrooms (Floor Common Area) with the tenants who occupy space on the same floor. Clearly, only tenants should proportionately share washrooms. Method A of the BOMA 2010 standard attempts to mitigate this disconnect by segregating Building Common Area into Building Amenity Areas and Building Service Areas. The key difference being that only Building Amenity Areas (and of course Tenant Areas) are grossed-up by Floor Service and Amenity Areas (previously known as Floor Common Area). Building Amenity Areas are defined as areas in a building that provide a convenience to all tenants of a building and could include conference rooms, daycare facilities, lounges, fitness centers and vending areas. Building Service Areas are defined as areas that are necessary for the building to operate and could include building mechanical and equipment rooms, building egress corridors and main and auxiliary lobbies.
Method B (Single Load Factor Method) Many property managers and building owners have expressed a desire to apply a single gross-up factor to all the tenants in a building. Method B of the BOMA 2010 standard provides this option and in doing so, introduces several new approaches and concepts to building measurement. The most controversial is the allocation of Base Building Circulation, which is basically the minimum path (based on the architectural features and local regulations) on a multi-occupant floor which is necessary for access and egress. The process of applying this new concept could be viewed as interpretive to some extent since a "hypothetical" corridor needs to be established on each floor regardless of occupancy or physical conditions. Building Amenity Area, Building Service Area and Floor Service Area, are also introduced (defined below) but are all incorporated into a single new common area type known as Service & Amenity Areas. Under BOMA 2010, Method B, Base Building Circulation and Service & Amenity Areas are represented as separate and distinct areas, but in the calculations, they are combined on a building-wide basis and proportionately distributed to all tenants of the building, establishing the single load factor.
Key BOMA 2010 Definitions
- AMENITY AREA is space within a building that adds a convenience to more than one tenant. Amenity Area can either benefit the occupants of a specific floor (Floor Amenity Area) or the entire building (Building Amenity Area).
- BASE BUILDING CIRCULATION (Method B Only) is the minimum, necessary path required (based on architectural features, local codes and other requirements) on a multi-occupant floor for access and egress.
- BUILDING SERVICE AREA is an area of a building that provides services that are necessary for building occupancy.
- EXTENDED CIRCULATION is a portion (usually within a corridor) of a tenant's area that is located outside of its physical boundries.
- EXTERNAL CIRCULATION is an unenclosed multi-occupant corridor which provides access and egress to tenant spaces. It must provide the only means of access and egress in order to be calculated as part of the rentable area.
- FLOOR SERVICE AREA is an area of a floor that provides services that are necessary for occupancy on that floor.
- LOAD FACTOR A is the total gross-up applied to tenants of a particular floor when using BOMA 2010, Method A.
- LOAD FACTOR B is the single total gross-up ratio applied to all the tenants in a building when using BOMA 2010, Method B.
- OCCUPANT AREA is the same as Office Area and Store Area in BOMA 1996. It is the areas of a building occupied by a tenant to house personnel, equipment, fixtures, furniture, supplies, goods and merchandise.
- OCCUPANT + ALLOCATED AREAS (Method A Only) is the same as Basic Rentable Area in BOMA 1996.
- OCCUPANT STORAGE is space within a building that is used by tenants but does not have the services and finishes (such as HVAC) required to be considered Occupant Area. Occupant Storage is accounted for separately and is not part of the rentable area of a building.
- VOID is the absence of a floor where a floor might otherwise be expected. A VOID is different than a Major Vertical Penetration and is not included in Method A or Method B calculations.