Sometimes, the square footage of a home according to the appraisal district doesn’t match up with an appraiser’s report. It’s not necessarily that the home was measured incorrectly in one instance or another; it’s likely a difference in the method each follows when calculating the house’s square footage, or gross living area.
The gross living area (GLA) of a home refers to the above-grade, finished living space. Garages and basements—any part below grade and however well finished—do not count toward the GLA. While condos and co-ops use the interior perimeter dimensions to calculate the GLA, for single-family homes, the exterior dimensions are used.
Builders often use the exterior dimensions of a home before the veneer is applied when calculating livable area. Floorplans might also include parts of the house in the total square footage that would be excluded by others from the GLA, such as garages, finished walk-out basements, or space on an upper level that is open to the level below.
An appraisal district measures the exterior dimensions of a home outside of the veneer then rounds each measurement—sometimes to the nearest foot—before calculating the area. Appraisal district measurements also may not exclude area where the home’s exterior is irregularly shaped, such as around a bay window, or parts of an upper level that are open to the level below. The appraisal district does not inspect the interior of homes and may not know what sections of upper floors are open to below, like a vaulted ceiling or the space for stairs.
Many appraisers follow the American National Standards Institute (ANSI) process and measure the exterior dimensions of a home outside of the veneer to the nearest inch or tenth of a foot and round only the final calculated square footage to the nearest foot. ANSI also requires appraisers to exclude areas that do not contribute to the livable area, such as areas open to the floor below or bay windows that do not extend to the floor. Appraisers also report basement or below-grade parts of the home separately from GLA. If any portion of the part of the home is below-grade, such as a walkout basement, it is excluded from GLA.
Sometimes confused with the GLA, the gross building area (GBA) is a measurement used mainly for multifamily properties that uses the exterior dimensions of a building, including all common spaces. For a single-family home, the GBA may or may not be the same as the GLA.
What Do You Tell Clients?
If you provide the square footage of a property or list it in the MLS, you should always quote the source of the information and let prospective buyers know if you have any reason to know that the information is false or inaccurate. The form Notice of Information from Other Sources (TXR 2502) is available to Texas REALTORS® for this purpose.