1. Nature of a House Math Estimate
House Math generates Estimates using automated rules, statistical relationships, and information retrieved from public records and publicly available listing sources, together with any facts you enter. An Estimate is a model output. It is probabilistic. Two competent methods can disagree by a wide margin on the same house. Publication of a number does not mean the number is correct, complete, or suitable for any particular purpose.
Where living area, bedrooms, bathrooms, or a sufficient set of similar nearby closed sales cannot be established, House Math may withhold a headline number rather than publish a figure that would be a guess. Withholding a number is not a representation that the property has no value.
2. Distinctions — what an Estimate is not
Unless a licensed professional separately engaged by you states otherwise, a House Math Estimate is not:
- Market value as determined by a willing buyer and willing seller in an arm’s-length transaction. Actual sale price can be higher or lower.
- Assessed or tax value as determined by a county appraisal district or similar authority. Tax assessed value often lags the market and follows statutory rules that are not the same as a sale.
- A licensed appraisal under USPAP or any state appraiser statute, and not an “evaluation” under federal interagency guidelines.
- A broker or agent CMA or BPO prepared by a licensed real-estate professional who has toured the property.
- A listing price, asking price, or cash offer.
- Purchase price you should pay or accept.
- Lending, insurable, or investment value.
Copied figures from listing websites, if shown, are those sites’ own published estimates. They are not House Math’s Estimate and are not appraisals.
3. Methodology (high level)
When a number is published, nearby closed sales of similar homes typically do most of the work. A recent sale of the same house, a list price if the house is on the market, neighborhood or index context, and tax-assessed value may be used as checks. Listing-site estimates may be retrieved for comparison and, when they cluster, may nudge the published number. We do not disclose weights, source code, or other trade secrets.
Different valuation methodologies — including cost, income, and sales-comparison approaches, and different comparable sets, time windows, and adjustments — may produce substantially different results. House Math does not inspect the interior or exterior of the property.
4. Factors that can make an Estimate wrong
Estimates may be affected by, among other things:
- incomplete, outdated, inaccurate, or unavailable property information;
- errors in living area, bedroom or bathroom count, lot size, or year built;
- property condition, deferred maintenance, and quality of finishes;
- renovations, additions, or unrecorded improvements;
- unique architecture, views, easements, flood, soils, or other site issues;
- location within a neighborhood, school assignment, and adjacent uses;
- the number, recency, and similarity of comparable sales;
- market liquidity, supply and demand, seasonality, and interest rates;
- economic conditions and changes after the Estimate is generated;
- data errors in public records or listing sites; and
- facts you enter that do not match the house.
An Estimate is a snapshot. It can become stale quickly. We have no duty to update a report after it is generated.
5. When you need a licensed appraisal
You should obtain an appraisal from an appropriately licensed or certified appraiser when an appraisal is required or prudent for mortgage lending, refinancing, private mortgage insurance, divorce, estate proceedings, probate, litigation, tax contests or filings, bankruptcy, eminent domain, government programs, or any other legally regulated purpose. A House Math Estimate is not “lender-grade,” “official,” “certified,” “USPAP-compliant,” or “guaranteed,” and must not be submitted as a substitute for an appraisal.
6. No financial, tax, legal, lending, or brokerage advice
House Math does not provide financial advice, investment advice, legal advice, tax advice, mortgage advice, lending decisions, real-estate brokerage advice, or fiduciary advice. Calculators, tax sketches, and forecasts are estimates based on assumptions and available inputs. They may not reflect actual future results. You remain responsible for independently evaluating information before making any decision.
7. Forward-looking sketches
Five-, ten-, and twenty-year figures, including any yearly-tax illustration, are hypothetical sketches using historical house-price indexes and, where available, a local effective tax rate. They assume continuation of trends that may not continue. Actual future sale prices and taxes can be much higher or much lower, including a loss of value. They are not a prediction on which you should trade or borrow.
8. Automated retrieval and models
The Service may use automated retrieval and language-model tools to locate publicly available listing and record information, and statistical or rules-based models to produce an Estimate. Those systems can misread a page, match the wrong house, or omit a sale. Outputs should be independently evaluated. We do not disclose proprietary algorithms.
This Disclaimer is incorporated into the Terms of Use. Related reading: Data Disclaimer and Consumer Notices.