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Appraisal Fundamentals

Gross Living Area (GLA) Explained

Why the square footage in your appraisal might not match your tax record — and why that's usually not an error.

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Appraisal Fundamentals5 min read

Gross Living Area (GLA) is the finished, above-grade square footage an appraiser measures and reports — and it's one of the most influential figures in the entire appraisal, since so much of comparable selection and adjustment is built around it.

What Counts Toward GLA

Above-Grade Only

GLA generally counts only finished, heated/cooled living area above grade — space with at least most of its walls above ground level.

Finished & Accessible

The space must be finished to a standard comparable to the rest of the home and accessible without going through unfinished areas.

Consistently Measured

Appraisers use a consistent measurement standard so a home's GLA can be fairly compared to other homes' GLA in the same market.

Above-Grade vs. Below-Grade Area

A finished basement, even a beautifully finished one, is generally reported and valued as below-grade area — separately from GLA — because buyers in most markets don't value below-grade space the same as above-grade living space. That doesn't mean it adds no value; it means it's analyzed on its own line rather than folded into the GLA figure that drives comparable selection.

What This Does Not Mean

A different GLA figure than you expected isn't automatically a mistake, and GLA isn't the same thing as "usable space" in every buyer's mind. It's a standardized measurement that lets an appraiser fairly compare your home to others — see how appraisers actually measure a house for the mechanics behind the number.

Frequently Asked Questions

Not always. Public records and listing sites sometimes use different measurement conventions or include space (like a finished basement) that doesn't count toward GLA under appraisal standards — see below-grade vs. above-grade area.

Generally no — finished basement or below-grade space is typically reported and valued separately from above-grade GLA, even though it can still add real value to the home.

Homes with similar GLA are generally more directly comparable, and GLA differences are one of the most common and significant adjustment categories in the Sales Comparison Approach.

Ask how the measurement was taken — appraisers commonly use a recognized exterior-measurement standard, which can differ slightly from interior-only measurements or builder-quoted figures.

Continue Learning

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Provided for general educational purposes based on ANSI Z765 and Fannie Mae/Freddie Mac appraisal reporting standards. Last reviewed: August 2026.

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