Gross Living Area, Above and Below Grade, from a Scan
“How many square feet?” sounds simple until you get to the basement. Gross living area is the number listings, appraisals, and buyers argue about most, and the argument is almost always about what counts. This guide explains the idea, shows how BeaverPlot separates above- and below-grade area from a scan, and is clear about what the number is and isn't.
What gross living area is
Gross living area (GLA) is the finished, heated, habitable floor area of a home that is above grade — above ground level on every side — measured from the exterior of the walls. Garages, unfinished attics, porches, and anything with even one wall below grade are excluded from GLA and reported separately.
That last rule is why basements are the sticking point. A finished walk-out basement can be beautiful, heated, and full of bedrooms, and it still isn't GLA under the usual appraisal convention. It is reported as below-grade finished area, and its value is considered on its own line.
Split above and below grade from a scan
Scan each level as its own story
Scan the main floor, then use the level controls to start the basement or upper floor as a separate story. Use Next Room at each doorway. The scanning guide covers the basics.
Calibrate first
In Edit Blueprint, measure one long wall with a tape and enter it; up to three walls are averaged. Area scales with the square of length, so a 2% length error is a 4% area error. Do this before you read any total.
Mark the basement below grade
Open the project's Levels section and turn on the Below grade toggle for the basement story. The totals split immediately into above-grade area and below-grade area. If your basement is partly below grade on any side, the convention treats the whole level as below grade — the toggle follows that.
Copy the GLA disclosure
Tap Copy GLA disclosure. You get a paste-ready paragraph with both numbers, the calibration status, and a plain statement that the figures are an estimate from a LiDAR scan and not an ANSI Z765 measurement. Paste it under the square-footage line in a listing, a report, or an email.
Carry it into the plan or report
The listing floor plan and the AI reports pick up the split, so a condition report or branded listing plan shows above- and below-grade area on the page rather than one combined total.
Why we don't call it ANSI
- Interior vs exterior. The scan sees inside faces of walls. The app estimates wall thickness to reach an exterior figure, and an estimate is not a measurement.
- Ceiling-height rules. ANSI excludes area under low ceilings and counts sloped ceilings by a specific rule. The scan reports floor area as scanned.
- Stairs, chases, and openings have their own treatment that a scan doesn't apply.
- Accuracy. Calibrated LiDAR is close, not certified. It is a starting template you can refine, and the disclosure says so.
If a lender, MLS, or client requires an ANSI-compliant figure, hire a measurement service or appraiser. Bring the scan — it makes their visit faster — but let their number be the number.
Common questions
Does a finished basement add value?
Often, yes — but it's valued as below-grade area, not as GLA. Report both numbers honestly and let the market and the appraiser do the rest.
What about a split-level or a walk-out?
Any level with a side below ground is conventionally treated as below grade. Toggle that level and say so in the disclosure.
Is this free?
Scanning, calibration, the Levels toggle, and the disclosure text are free. Exporting the plan or a report needs Pro or Pro AI; see Pro & billing.
Two numbers, one disclosure, no overclaiming. That is more than most listings manage.
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