# ANSI-conforming square footage from the scan

> weScan measures to the exterior finished surface, applies the ANSI Z765-2021 ceiling-height rules room by room and reports non-standard area separately.

Source: https://wescan.io/en/market-us

## 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.

[Book a demo](#demo)

[See a sample report](#spec)

## 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

Single-family · detached and attached

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.

- Approved April 2021
- Not for apartments / multifamily

### Fannie Mae

Appraisals · Selling Guide B4-1.3-05

“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.

- Selling Guide, 06/04/2025 version
- Hybrid and full appraisals

### UAD 3.6

Appraisal data

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.

- Mandate: Nov 2, 2026 (Freddie Mac)
- Temporary exceptions on request

## 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.

ext. (walls)

### Minimum ceiling height

Finished area needs at least 7 ft (2.13 m); 6 ft 4 in under beams and ducts.

7 ft (ceiling)

### Nothing lower counts

Under a sloped ceiling no finished area lower than 5 ft (1.52 m) is included.

5 ft (sloped ceilings)

### Half must reach 7 ft

In a room with a sloped ceiling, at least half the finished area must be 7 ft or higher.

½ (sloped rooms)

### Counted where they descend from

Treads and landings count on the floor the stairs descend from; openings to the floor below do not.

stairs (and landings)

### Reported separately

Any level partly below grade is below-grade area and never added to above-grade totals.

below (grade)

## What your client receives.

Sample figures from the drawn sample attic used on our home page; the layout follows your house style.

## Plans we delivered in this market.

Addresses and client details removed.

- 2D: Lower level · sq ft per room
- 2D: Garage with first floor
- 2D: Main floor · furnished
- 3D: Main floor
- Garden: Garden drawing · pool and terraces
- Garden: Garden drawing · the same plot in 3D
- Garden: Garden drawing · pond and paths
- Garden: Garden drawing · the same plot in 3D

## 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.

Nov 2, 2026

Freddie Mac, Uniform Appraisal Dataset page

## One stop shop: everything from one scan.

- 2D floor plans (sq ft)
- 3D floor plans
- ANSI Z765 square footage report
- Appraisal sketch
- CAD: DWG · DXF
- BIM: IFC · Revit-ready
- Site plan
- Virtual tour

## Bring us one property.

We show you the plans and the report for United States, in your house style.

[Book a demo](mailto:info@wescan.io?subject=Demo)

[info@wescan.io](mailto:info@wescan.io)