Why Appraisers Adopted ANSI Home Measurement Standards
By Joseph T Ellington Jr – Licensed Residential Appraiser, Capital Valuations.
Last updated
This article originally discussed the adoption of ANSI Z765-2021 for Fannie Mae appraisal assignments. The core question remains: why can a freshly measured appraisal show a different square-footage figure from an older listing or tax record? The standard supplies a consistent method for measuring and reporting area. Capital Valuations also offers home measuring services as a separate assignment when you need documented square footage rather than a value opinion. It does not guarantee every public record will match, and it does not mean every private assignment or property type uses the same lender rule.
What changed for applicable lender reports?
Fannie Mae’s current Selling Guide sets out above- and below-grade area and ANSI requirements for covered assignments and identifies exceptions. An appraiser documents dimensions and reports categories according to those rules, rather than automatically copying a tax-card figure. The more detailed companion article, our ANSI Z765-2021 appraisal guide, explains how the standard applies today.
Why numbers from tax and MLS records differ
A tax-card figure may be outdated or use a different reporting convention. An MLS listing may reproduce builder, owner or assessor data without an independent measurement. An appraisal sketch may reflect a measured dwelling and a specific report method, including separate categories for above- and below-grade finished space. Compare the underlying dimensions and dates before calling one figure an error.
Joe’s experience with records that do not agree
In my measurement work, I often find that the public record, a previous listing and a current sketch are not describing precisely the same thing. The difference may reflect an older record, a changed house or a different method. I check what was included and the source of the dimensions before deciding what needs correction.
The sketch is useful because it makes the measurement traceable. My measurement-only deliverable is a PDF with exterior dimensions, room labels and square-footage calculations. Garages, porches, decks and areas that do not qualify as living area are identified separately. Interior dimensions are available when requested and included in the agreed scope.
Dimension precision is different from area rounding
For applicable ANSI-based appraisal reporting, measurements are recorded to the nearest tenth of a foot and final area to the nearest whole square foot. This does not mean that an agent should round a completed 1,570-square-foot result up to 1,600 for marketing. See Fannie Mae’s measurement guidance and confirm the requirements for the assignment.
Before listing, compare the sketch with what will be entered in each MLS field. Our guide to verifying listing square footage explains the source checks and how to handle a discrepancy. Request a home measurement if you need a documented area calculation without a market-value opinion.
A comparison to review before listing
| Source | Possible reason for a difference |
|---|---|
| Tax record | Older property data, an addition not reflected, or a different convention |
| MLS listing | Builder, owner or assessor figure supplied without new measurement |
| Appraisal sketch | Measured area and stated reporting method with separate area categories |
What owners and agents should do
- Ask what the figure includes, who measured it, and when.
- Keep plans and permits, but compare them with the actual finished property.
- If a listing conflicts with a new sketch, verify dimensions and area definitions before revising marketing material.
- Do not turn a measurement difference into an automatic dollar adjustment; market evidence controls value analysis. See our area-adjustment guide.
Private appraisal questions
This 2022-era adoption topic is retained as a historical explanation, while the companion guide addresses current reporting rules. For a private residential appraisal in Hampton Roads, contact Capital Valuations with the property and intended use.
