ANSI-conforming square footage. Straight from the scan.
Fannie Mae requires appraisers to follow ANSI Z765-2021 for above- and below-grade area, and says output from sketching or 3D scanning software must conform. weScan measures to the exterior finished surface, applies the ceiling-height rules room by room and reports what does not conform, separately and with the reason.
The standard behind the number.
For single-family homes, the square footage an appraiser reports is defined by one standard, and the GSEs say so explicitly, including for scan-based sketches.
ANSI Z765-2021
Square Footage – Method for Calculating. Finished area per level, measured to the exterior finished surface; above-grade and below-grade kept apart; ceiling-height rules for what may count.
Fannie Mae
“When using sketching or 3D scanning software, the resulting output must conform to the ANSI standard.” Non-standard finished area is calculated and reported separately, with the reason.
UAD 3.6
The redesigned uniform appraisal dataset becomes mandatory on 2 November 2026. Clean, per-level area data from the scan drops straight into the new forms.
Six rules that change the number.
Exterior finished surface
Each level is measured at floor level to the exterior finished surface of the outside walls.
Minimum ceiling height
Finished area needs at least 7 ft (2.13 m); 6 ft 4 in under beams and ducts.
Nothing lower counts
Under a sloped ceiling no finished area lower than 5 ft (1.52 m) is included.
Half must reach 7 ft
In a room with a sloped ceiling, at least half the finished area must be 7 ft or higher.
Counted where they descend from
Treads and landings count on the floor the stairs descend from; openings to the floor below do not.
Reported separately
Any level partly below grade is below-grade area and never added to above-grade totals.
What your client receives.
Sample figures from the drawn sample attic used on our home page; the layout follows your house style.
Square Footage Report
| Level | Finished | Unfinished | Non-standard | Grade |
|---|---|---|---|---|
| Main level | 419 | — | 184 (dining) | Above |
| Upper level | 454 | — | — | Above |
| Lower level | 612 | 298 | — | Below |
| Garage | — | 200 | — | — |
| Finished above-grade | 873 sq ft |
Sample figures · drawn sample houseCHECKED
BY A
PERSON
- 01
ANSI-conforming totals
Finished above-grade, below-grade and unfinished areas, reported separately as Fannie Mae asks.
- 02
Ceiling-height checks
7 ft minimum, nothing under 5 ft below slopes, the one-half rule for sloped rooms flagged per room.
- 03
Non-standard finished area
Areas that fail the height rules are listed separately with the reason.
- 04
Sketch for the appraisal
Exterior-dimension sketch with sq ft per level, ready for the report.
- 05
Your brand
Your logo and license details on the cover.
Plans we delivered in this market.
Addresses and client details removed.
Rules move. Reports follow.
UAD 3.6 becomes mandatory
Appraisals move to the redesigned Uniform Appraisal Dataset. Square footage that already follows ANSI Z765 and is split by level and grade is the input the new forms expect.
One stop shop: everything from one scan.
Bring us one property.
We show you the plans and the report for United States, in your house style.