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How to Check an Appraisal for Errors With AI
By Jason Taken · Principal, Jaken Finance Group
8 minute read
Check appraisal facts and adjustment math with AI-assisted ROV help. Free for current Jaken Finance Group borrowers; $99 one-time for non-borrowers.
To check an appraisal for errors, compare its property facts with supporting records, reproduce the reported calculations, and document discrepancies by page. AI can extract and organize the information quickly. A person must verify the original figures and determine whether the issue is an error, a missing fact, or a question about judgment.
A low value alone does not identify a mistake. Begin with a specific statement you can check. That approach produces a clearer reconsideration of value, or ROV, than asking an AI system to justify the number you hoped to receive.
Need assistance? Jaken Finance Group researches and drafts ROV requests free for current borrowers. Non-borrowers pay a one-time $99 fee for the research and draft. Request a callback about your appraisal and describe the issue you want checked.
Which appraisal problems can you check yourself?
Separate the review into three categories. This helps you choose useful evidence and avoid presenting an opinion as a proven mistake.
| Category | Example | What to collect |
|---|---|---|
| Factual discrepancy | Two report sections show different bathroom counts | Page references, photos, and supporting property documents |
| Arithmetic discrepancy | Listed adjustments do not produce the displayed total | Original inputs and a reproducible calculation |
| Analytical question | A condition adjustment appears unexplained | Report commentary and relevant market evidence |
The third category needs particular care. You may reasonably ask for an explanation without claiming that you have established the correct adjustment. A different online estimate or a renovation invoice alone does not prove the appraisal’s conclusion is wrong.
Our AI-assisted ROV guide explains how these findings fit into the lender’s reconsideration process. Here, the focus is finding and documenting issues before drafting the request.
Start with the report version and effective date
Read the complete appraisal, including addenda and revisions. Record the property address, effective date, report date, and version. The date the report was delivered may differ from the date its value conclusion describes.
Keep your working notes separate from the original. If a lender sends a revised report, compare the revision with your findings log before adding another concern. Otherwise, you may challenge a statement that has already been corrected.
Collect supporting records that relate to the relevant period. A photograph taken after substantial improvements may accurately show today’s condition while failing to show the condition considered in the appraisal. Label dates rather than leaving the reader to guess.
How can AI compare property facts across a report?
Ask the model to extract a limited set of fields: address, property type, room counts, finished areas, year built, condition descriptions, and reported improvements. Require a page reference beside every entry.
Next, ask it to identify conflicting entries within the report. This is a smaller, more useful task than asking whether the appraisal is “good.” A model might spot a garage described differently in the summary and comparable grid; you can then inspect both locations.
Scan quality matters. Optical character recognition can turn a minus sign into a dash, omit a decimal, or read $18,000 as $13,000. Verify flagged entries against the actual PDF image before treating them as report errors.
Use a findings table with four columns: report statement, supporting record, discrepancy, and question. “Please confirm whether the description should include the attached garage shown in the photographs” is specific enough to investigate.
What if the square footage appears wrong?
Compare definitions before comparing totals. Tax records, listing information, floor plans, and appraisals may classify finished space differently. A mismatch is a reason to investigate, not an automatic correction.
Fannie Mae’s guidance distinguishes above-grade, below-grade, and certain separately reported finished areas. It applies specified measurement standards to covered single-family appraisal assignments. A finished walk-out basement, for example, may contribute value while being reported separately from above-grade area. Fannie Mae improvements and measurement guidance.
Ask AI to compare the sketch, room descriptions, and area totals. Then inspect the relevant dimensions and classifications yourself. If you cannot establish the correct measurement, frame the finding as a request to reconcile the records or explain the classification.
Avoid multiplying a disputed area by a neighborhood’s average sale price per square foot and calling that the missing value. That calculation combines several assumptions that your records may not support.
How do you check comparable-sale adjustment math?
Start with the sale price shown for one comparable. Add each positive adjustment and subtract each negative adjustment. Compare the result with the report’s adjusted sale price.
The arithmetic checks whether the displayed numbers agree. It does not establish that the adjustment amounts are appropriate. Fannie Mae requires market-supported adjustments and cautions against unsupported rules of thumb. Fannie Mae adjustment guidance.
The checker below also calculates net and gross adjustment percentages. Net adjustments preserve the signs; gross adjustments add the absolute amounts. Both use the comparable’s sale price as the denominator. They are descriptive calculations, not pass-or-fail limits.
Enter the amounts exactly as reported. Include all adjustment lines and check the addendum for explanations. A blank field means an input is missing; enter zero only when the relevant amount really is zero.
Worked example: a $4,000 discrepancy
Assume a fictional comparable sold for $360,000. Its report shows a positive $12,000 adjustment and a negative $4,000 adjustment. The displayed adjusted sale price is $364,000.
The arithmetic is $360,000 + $12,000 − $4,000 = $368,000. Net adjustments total $8,000, or approximately 2.22% of the sale price. Gross adjustments total $16,000, or approximately 4.44%. The calculated adjusted price exceeds the displayed figure by $4,000.
A useful finding reads: “Please verify the adjusted sale price for Comparable 2. The two listed adjustments produce $368,000, while the report displays $364,000. Please identify any additional adjustment or correct the displayed calculation.”
That finding does not establish a $4,000 increase in the subject’s final value. The appraiser must consider the comparable within the full analysis. Fannie Mae’s reconciliation guidance emphasizes analysis of the available evidence and approaches rather than an unexplained average. Valuation analysis and reconciliation.
Which apparent errors may have a reasonable explanation?
A reported condition category may reflect more than the age of one improvement. A newer roof can coexist with other deferred maintenance. Compare the complete description before concluding that the appraisal ignored the work.
A sale outside an arbitrary radius may compete with the subject more closely than a nearby property with a different use or design. Ask why the selected transaction is relevant, and supply evidence of a better comparison when available.
Similarly, a final value does not need to equal the arithmetic midpoint of the adjusted comparable prices. Read the reconciliation discussion. If the weighting is unclear, ask for clarification rather than replacing it with your own average.
For research that goes beyond checking existing figures, follow our comparable-sale evidence guide. Keep that research separate from the arithmetic results so the lender can see exactly which concern is being raised.
Use this prompt to create a findings log
Review the supplied appraisal for internal inconsistencies and arithmetic discrepancies. Extract the original numbers with page references. Separate factual conflicts, calculation checks, and questions requiring professional judgment. Use only the supplied documents. Mark unreadable or missing information as unresolved. Do not invent adjustments, comparable sales, or a target value. Return a findings table and list the checks a person must complete.
Give the model only the information needed for the task, using a document-handling process appropriate for the file. Before sharing a complete borrower report, check the tool’s privacy settings and your authorization to use the documents.
The prompt produces working notes. Verify every finding against the report before copying anything into an ROV. If the model cannot show where a number came from, remove the claim or obtain the missing evidence.
How do you turn findings into an ROV request?
Prioritize the issues with the strongest documentation. For each, attach the relevant excerpt or record and explain the question in plain language. Keep the original wording visible so the lender can reproduce your comparison.
Use the ROV letter template to assemble the request. Ask your lender whether a minor correction belongs in a separate process and which submission requirements apply to your loan.
If you have identified a discrepancy but need help researching it, request Jaken Finance Group’s research and drafting assistance. Current borrowers receive the service free; non-borrowers pay $99 once. The callback is also the place to explain a tight deadline or missing documents.
Questions about checking appraisal errors
Does a higher tax assessment prove the appraisal is wrong?
No. Record the assessment’s date, purpose, and property description, then investigate specific differences. A tax assessment and a mortgage appraisal can involve different assumptions. The useful evidence is the verified underlying fact, not simply whichever value is higher.
Can the adjustment checker tell me what my home is worth?
No. It reproduces arithmetic from the amounts you enter. It does not select comparable sales, judge market-supported adjustments, or reconcile the subject property’s value. Correct arithmetic can still use an input that needs clarification.
What if AI flags something that is already explained?
Read the referenced page and addendum, then mark the finding resolved. Removing unsupported concerns improves the remaining request. You do not need to include every issue the model initially suggested.
Can I request help without finding a definite error first?
Yes. Describe the concern and share what you have through the agreed document channel. Research may confirm a discrepancy, identify a question needing explanation, or show that the original statement is supported.
How much does help with the research and draft cost?
Jaken Finance Group provides this service free to current borrowers. Non-borrowers pay a one-time $99 fee to research and draft the ROV. Request a callback to discuss the report and the next step.