Appraisal assumption treated as true for the analysis even though it could affect value if wrong.
An extraordinary assumption is an appraisal assumption treated as true for the analysis even though it could affect value if the assumption is wrong.
Extraordinary assumption matters because it flags uncertainty inside the valuation. The appraisal may be usable only if the stated assumption turns out to be true.
For mortgage borrowers, the term matters when the report depends on information that has not been fully verified, a condition that may change, or a fact that could materially affect collateral value.
Borrowers encounter extraordinary-assumption language in the Appraisal Report, often in the assignment conditions, comments, or limiting conditions.
The term becomes practical when underwriting or appraisal review asks whether the assumption needs support before the loan can close.
| Report language | Borrower-facing meaning |
|---|---|
| Assumption is stated | The appraiser is relying on a condition as true |
| Assumption could affect value | The value might change if the assumption is wrong |
| Lender review may follow | The file may need documentation or clarification |
An appraiser completes a report assuming a certain repair or condition is as represented. If that assumption is not true, the value conclusion could be affected, so the lender may need follow-up before relying on the report.
Extraordinary assumption differs from Hypothetical Condition because an extraordinary assumption is treated as true but uncertain, while a hypothetical condition is knowingly contrary to current fact or not yet true for the analysis.
It differs from Subject-To Appraisal because subject-to appraisal describes a value conditioned on completion or correction of specified items.
It also differs from Appraisal Review because review is the lender-side check that may evaluate whether the assumption is acceptable.