This is a simple question, and certainly fair one for a tenant to ask.  The answer, however, can be complicated.  Depending on the nature of a building, the method used to calculate the area of a space can vary.  In a typical retail center, space is measured from the centerline of tenant separation walls and to the exterior side of exterior walls.  This allows a Landlord to rent 100% of the floor area of the building, including the floor area contained within tenant separation walls.  In this way, if a Landlord has one 10,000 SF Tenant or 10 1,000-SF Tenants, the Landlord has the same rentable area.  This same general theme applies to small, single story office buildings that have no common area.

Multi-story office buildings present a different challenge.  Generally, these building have interior common areas including corridors, restrooms, fire stairs, etc.  In most cases, building owners want to include those common areas as part of the building’s total rentable area.  In an effort to accomplish this goal, two area calculations are often found in a Tenant’s lease.  The “useable” area of a space is just that; the number of SF contained within the four walls of the space.  The second calculation is referred to as the “rentable” area of the space.  This figure includes a proportional share of the building’s common areas.  Stated differently, the rentable area includes a share of the common corridors, restrooms, etc.  The theory is that all tenants use and benefit from these common areas and they need to pay for them.  In order to compare the economics of various buildings, it is important for Tenants to know if their rent is calculated based on the useable or rentable area.

This is a very simplified discussion of how space is measured.  Dedicated readers may want to refer to the professional organization Building Owners & Managers Association  (“BOMA”) at  www.boma.org for a more detailed explanation of the many ways to calculate the area of a space.