1. Build the subject-property fact sheet first
You cannot choose useful comparable sales until you know what is being compared. Record the exact address and unit, property type, legal use, site or lot, finished living area, bedroom and bathroom count, age, parking, material renovations, condition evidence, and location influences. When public, listing, or seller data conflict, record the conflict instead of choosing the most convenient number.
The fact sheet is a search specification, not a claim that every listed feature is verified. A converted room, finished basement, accessory unit, or addition may need permit, appraisal, title, or professional confirmation.
2. Build candidates from closed sales, then widen deliberately
A strong candidate is a sale that competed for broadly the same buyer. Begin with recent closed sales of the same property type in the relevant market area. If the set is thin, widen one dimension at a time—date, distance, size, or another feature— and record why the wider candidate remains useful.
Fannie Mae's appraisal guidance says appraisers should consider sales that appeal to the same market participants and explain why older or more distant sales are used. That is useful analytical discipline for a buyer, but it is not a DIY rule that every buyer must use a fixed number of sales, miles, or months.
Active and pending listings can show current competition, but they are not closed price evidence. A list price is an asking decision; a closed sale records a completed transaction, subject to the quality of the underlying data.
3. Verify the transaction, not just the address
For every candidate, try to confirm:
- whether it actually closed, and the contract or closing date available to you;
- whether the parties appear unrelated and the sale appears market-exposed;
- seller or financing concessions when that information is available;
- whether the recorded property matches the marketed property;
- whether major condition, renovation, view, site, parking, or legal-use facts differ;
- whether the source is current enough for the decision you are making.
Public records can lag, listing data can be corrected, and concession details may not be publicly available. “Not found” is a source status, not evidence that no concession or material difference existed.
4. Compare differences without inventing adjustment dollars
Price per square foot is a context measure, not a valuation formula. It compresses condition, site, layout, location, parking, renovations, and other differences into one denominator. A smaller renovated home and a larger dated home can have very different prices per square foot without either number transferring cleanly to the subject.
Record each material difference and ask whether local paired sales or another credible market source supports an adjustment. If you cannot support an adjustment, keep the difference qualitative or reduce that comp's influence. Avoid national bedroom, bathroom, pool, view, age, or condition dollar amounts.
5. Separate market movement from property differences
An older sale may need market-condition analysis. A broad house-price index can provide context, but it cannot establish how one particular home's value moved. Local property type, price tier, neighborhood, condition, inventory, and financing conditions may behave differently from a metro or national average.
Use time adjustments only when the relevant local evidence supports them. Otherwise, label the sale older, show the uncertainty, and look for a more current cross-check.
6. Reconcile the evidence instead of averaging everything
Group candidates into three buckets:
- Keep: verified enough, competitively similar, and useful for the conclusion.
- Verify: potentially useful, but a material fact, concession, status, or source conflict remains unresolved.
- Reject: not competitive, not verifiable enough, or likely to distort the view.
Weight the strongest verified evidence more heavily. Look for bracketing—sales above and below the subject on important features—and watch for one sale dominating the result. Publish a range that reflects comparable dispersion and unresolved facts. Do not call it a calibrated probability interval unless it has actually been tested out of time for the relevant market and property segment.
A printable comp evidence ledger
| Field | What to record | Decision use |
|---|---|---|
| Source and status | URL, provider, date, sale status | Define what the record supports |
| Sale timing | Contract/closing/recording date available | Compare market conditions |
| Competitive fit | Type, location, size, rooms, site, age | Explain why the sale belongs |
| Condition and work | Condition, renovations, permits if known | Flag material differences |
| Concessions | Amount or “not available” | Avoid treating net terms as identical |
| Adjustment support | Local evidence or unresolved | Prevent invented dollar changes |
| Keep / verify / reject | Decision and written reason | Preserve the audit trail |
| Remaining question | Fact, owner, source, deadline | Route the gap to the right professional |
Know what kind of value product you are reading
An automated valuation model, broker price opinion, buyer research report, and licensed appraisal have different producers, purposes, evidence, and legal roles. During a mortgage transaction you may receive more than one valuation, and the figures can differ. The CFPB explains that different valuations can use different data, timing, and methods.
Twellie is buyer research software. Its evidence range and comp ledger do not replace a licensed appraisal, lender decision, broker opinion, inspection, or legal review. Use the sample report to see how accepted and rejected evidence is shown, then read the methodology for the current calculation and readiness rules.
Turn the ledger into better offer questions
Before relying on the range, ask which subject facts remain unverified, which comp has the greatest influence, whether concessions or condition could change the comparison, and what happens if the strongest comp is removed. Route physical condition to an inspector, title or legal-use questions to the appropriate title or legal professional, and financing/appraisal questions to the lender and appraiser.
Continue with the home-buyer due-diligence checklist. A price view is only one part of the decision.