The purpose of the Standard Method For Measuring Floor
Area in Office Buildings is to permit communication and computation on a clear
and understandable basis. The BOMA Standard has been the generally accepted method
for measuring office space for many years. It should be noted that this standard
can and should be used in measuring office space in old as well as new buildings.
It is applicable to any architectural design or type of construction. Usable
Area - This method measures the actual occupiable area of a floor or an office
suite and is of prime interest to a tenant in evaluating the space offered by
a landlord and in allocating the space required to house personnel and furniture.
The amount of Usable Area on a multi-tenant floor can vary over the life of a
building as corridors expand and contract and as floors are remodeled. Usable
Area can be converted to Rentable Area by the use of a conversion factor. The
Usable Area of an office shall be computed by measuring to the finished surface
side of the office side of corridor and other permanent walls, to the center of
the partitions that separate the office from adjoining Usable Areas, and to the
inside finished surface of the dominant portions of the permanent outer building
walls. No deduction shall be made for columns and projections necessary to the
building. The Usable Area of a floor shall be equal to the sum of all Usable
Areas on that floor. Rentable Area - This method measures the tenant’s
pro-rata portion of the entire office floor, excluding elements of the building
that penetrate through the floor to areas below. The Rentable Area of a building
is fixed for the life of a building and is not affected by changes in corridor
sizes and configuration. This method is therefore recommended for measuring the
total income producing area of a building and for use in computing the tenant’s
pro-rata share of a building for purposes of rent escalation. The Rentable Area
of floor area shall be computed by measuring to the inside finished surface of
the dominant portions of the permanent outer building walls, excluding any major
vertical penetrations of the floor. No deduction shall be made for columns
and projections necessary to the building. The Rentable Area of an office on the
floor shall be computed by multiplying the Usable Area of that office by the quotient
of the division of the Rentable Area of the floor by the Usable Area of the floor
resulting in the R/U Ratio. Load Factor - The Load Factor is the
percentage of space on a floor that is not usable, expressed asa percent of Usable
Area. It is also known as the Common Area Factor or the Loss Factor.
|
Load Factor (Load) = R/U Ratio - 1. | |
Conversion Formulas |
| Rentable Area ÷ Usable Area | R/U
Ratio | | Usable Area x R/U Ratio | Rentable
Area | | Rentable Area ÷ R/U Ratio | Usable
Area | | Usable Area x (1 + Load) | Rentable
Area | 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 paneling, furring strips and carpet. Dominant
Portion - That portion of the inside finished surface of the permanent
outer building wall which is 50% or more of the vertical floor to ceiling dimension
measured at the dominant portions. If there is no dominant portion, or if the
dominant portion is not vertical, the measurement for area shall be to the inside
finished surface of the permanent outer building wall where it intersects the
finished floor. Major Vertical Penetrations - Stairs, elevator shafts,
flues, pipe shafts, vertical ducts, and the like, and their enclosing walls, which
serve more than one floor of the building, but shall not include stairs, dumb-waiters,
lifts, and the like, exclusively serving a tenant occupying offices on more than
one floor. | 
