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GLA vs Total Square Footage: What Is the Difference?
If you have ever seen a listing say 2,400 sq ft but an appraisal report say 1,900 sq ft, you have seen the GLA vs total square footage problem in action. These are not the same measurement, and understanding the difference can save you from a surprise at closing.
The one-sentence version
GLA (Gross Living Area) is above-grade finished living space only. Total square footage can mean anything — it depends entirely on who calculated it and what they decided to include.
What GLA includes and excludes
Under ANSI Z765 — the standard licensed appraisers are required to follow — GLA is defined as heated, above-grade finished living space. That means:
- Included: Above-grade bedrooms, living rooms, kitchens, bathrooms, hallways, finished attics with 7-foot ceilings over at least half the space
- Excluded: Basements (even finished walkouts), garages, unfinished attics, covered porches, utility rooms below grade
A finished basement is reported separately in an appraisal — it contributes value, but it does not count toward GLA. This is a hard rule under ANSI Z765, not a judgment call.
What "total square footage" usually means
There is no universal standard for "total square footage" on a real estate listing. An agent might include:
- Above-grade space only (same as GLA in many cases)
- Above-grade + finished basement combined
- Everything under the roof including garage, porches, and unfinished areas
- Whatever the county assessor has on record (which uses its own methodology)
MLS systems vary by region on what they require agents to report. In many markets, there is no enforcement. The number you see on Zillow or Redfin is often just whatever the listing agent entered.
Why appraisers use GLA instead of total square footage
Consistency. When an appraiser compares your home to three recent sales in the neighborhood, all four homes need to be measured the same way. GLA under ANSI Z765 is the standard because it removes the judgment calls that cause inconsistency.
A 1,800 sq ft above-grade home with a finished basement sells for more than a 1,800 sq ft above-grade home without one — but the GLA is the same. Appraisers adjust for the basement separately rather than lumping it into the headline number.
Common scenarios where the numbers differ
- Finished walkout basement: Listing says 2,400 sq ft (including 600 sq ft basement). Appraisal GLA: 1,800 sq ft. Both are correct — they are measuring different things.
- Split-level home: The entry level may be partially below grade. Under ANSI Z765, the below-grade portion of that level is excluded from GLA even if it looks and functions like living space.
- Garage conversion: If a garage was converted to living space without proper permits and ceiling height, the appraiser may exclude it from GLA regardless of how finished it looks.
- Cape Cod / knee walls: Finished rooms under sloped ceilings count toward GLA only if they meet minimum ceiling height requirements (typically 5 feet minimum with at least half the floor area at 7+ feet).
Which number matters for your loan?
For most residential mortgage financing, the lender cares about appraised value — not square footage. But GLA is one of the primary inputs appraisers use to select comparable sales and make adjustments. A meaningful discrepancy between listed square footage and appraised GLA can affect value, especially if comparable sales were selected based on the inflated listing number.
If you are buying a home and the listing shows 2,400 sq ft but the appraisal comes back at 1,800 sq ft GLA, there is probably a 600 sq ft finished basement in the mix. That may or may not affect the appraised value depending on how the basement is treated in the comparable sales analysis.
How to calculate GLA yourself
If you have a floor plan — from an old appraisal, a listing PDF, or a sketch — you can calculate GLA without hiring an appraiser. PlanSnapper lets you upload any floor plan image or PDF, trace the above-grade perimeter, set one known wall length, and get an accurate GLA calculation in minutes. It follows ANSI Z765 conventions and exports a report you can use for reference.
Calculate GLA from any floor plan
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