BOMA Space Measurement Standard

Tips for Measuring:


Single-tenant office or industrial building

In an office or industrial building with a single user, square footage measurements are simple to calculate.

  • Measure from the middle of the exterior wall:  For ease of measurement, begin at a doorway or window in order to gauge the center of the exterior wall.
  • Measure to the middle of the opposite wall.
  • This measurement results in the usable square footage of the building and is equivalent to the space that is available for use  by the building occupant.


Multi-tenant office

The Building Owners’ and Managers Association (BOMA) is widely known as the go-to organization for standards of measurement for multi-tenant office buildings.  A detailed summary of the standards is available for purchase at this link:


Also, BOMA provides training for the 2010 Office Standard, both with trained instructors and also through a webinar that can be found at   The training includes:

  • Review the 7 factors driving the changes to the BOMA 2010 Office Standard
  • Explain the new terminology and concepts in the new Standard
  • Examine the features and organization of the new Standard
  • Distinguish and choose between the two calculation methods offered in the new Standard
  • Explain the five simple steps to measuring office space
  • Offer the correct lease language to cite the new Standard
  • Review the main features of the BOMA 1996 Office Standard

Instructor: William Tracy, MBA, NCARB, Building Area Measurement LLC, Vice Chair, BOMA International Floor Measurement Committee. Bill was the principal author of the new Standard and is one of the industry’s leading experts on floor measurement standards.

For more information on these training workshops scheduled in our community, contact

For more information about course content, email

Another opportunity to learn more about the new Office Standard is through  BOMA’s “on-demand” webinar entitled, What’s New?  Understanding BOMA’s Revised Floor Measurement Standard for Office Buildings

The complexity of calculating square footage in multi-tenant office buildings stems from the fact that a tenant has both “Usable Area” and “Common Area” that she enjoys.

Usable Area:  The space that a tenant occupies exclusively

Rentable Area:  Usable area plus the space common to all tenants, including lobbies, restrooms, and sometimes kitchens, conference rooms, and other shared spaces within a building.

In our community, we’ve seen rentable area to be anywhere from 8% to more than 20%  of the total square footage in a building.  Building efficiency is important to total rents, of course, but one of the top Class A buildings has lots of common area space.  The feel of that building is open and expansive.

The Math:  This chart was developed by Office Finder, and is a great illustration of usable versus rentable.

Load Factor (Load) R/U Ratio – 1
(Usable Area x R/U Ratio) Rentable Area
Rentable Area ÷ R/U Ratio Usable Area
Usable Area x (1 + Load) Rentable Area