By Joseph T Ellington Jr – Licensed Residential Appraiser, Capital Valuations. Updated September 2026.
Fannie Mae and ANSI Z765-2021: what homeowners should know
Two homes can be advertised with similar square footage yet use different measurement conventions. For many Fannie Mae appraisal assignments, ANSI Z765-2021 supplies a consistent method for measuring and reporting a dwelling’s above- and below-grade areas. This is a reporting standard, not a formula that increases or decreases market value on its own. Room count is a separate question; see how appraisers evaluate bedroom classification alongside area reporting.
What does the current Fannie Mae guide require?
Fannie Mae’s Selling Guide section B4-1.3-05 requires the ANSI Z765-2021 standard for measuring, calculating, and reporting the above- and below-grade square footage of applicable dwellings. If a state law or regulatory requirement requires another standard, the appraiser must explain the alternate standard. In 2025, Fannie Mae retired its earlier ANSI exception code and aligned terminology. Requirements depend on the assignment and property type; its desktop appraisal policy says ANSI is encouraged when feasible but is not required for desktop appraisals.
Why an MLS figure can differ
A listing, tax record, prior sketch, and current appraisal may describe the same house with different figures because of measurement method, unavailable plans, additions, or differences in reporting below-grade space. Do not assume one figure is fraudulent. Identify the source, date, included areas, and method used. An appraiser still needs to analyze how the local market treats a property’s features and competing sales.
| Check | Why it matters |
|---|---|
| Above-grade and below-grade areas | They may be reported separately even if both are finished |
| Additions and permits | Records may lag behind the current building |
| Attached versus detached spaces | A garage or accessory building is not automatically counted as living area |
| Measurement date and method | Older figures may use a different source or standard |
What to do if you see a discrepancy
- Compare the appraisal’s sketch and area description with your property records.
- Gather permits, plans, prior measurements, and clear photographs for an addition or unusual space.
- For a lender-ordered appraisal, raise a specific suspected error through the lender’s reconsideration of value process. An error correction may or may not change the opinion of value.
For the hands-on process, read how to measure a property. For how appraisers analyze size differences against sales, see square-footage adjustments. Our Virginia Beach service page explains local appraisal services.
Does a larger measured area guarantee a higher appraisal?
No. A valuation depends on market evidence, condition, location, other features, the assignment scope, and relevant comparable sales. A corrected area can affect analysis but does not establish a specific dollar change.
Have a question about a private appraisal in Hampton Roads? Contact Capital Valuations and explain the intended use.
