After Repair Value (ARV): The Foundation of Every Deal
ARV is the single most important number in a fix-and-flip deal. Master the art and science of estimating it accurately.
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Property Valuation6 min read
Using Zillow Zestimates Correctly as an Investor
Zestimates are imperfect but useful when interpreted correctly. Learn to extract signal from the noise.
Zillow's Zestimate is the most widely referenced automated valuation model (AVM) in residential real estate. According to Zillow's own published error rates, the nationwide median error for on-market homes is roughly 2%, while for off-market homes it's closer to 7%. These averages hide significant variation, some markets and property types have median errors exceeding 15%.
For fix-and-flip investors, the Zestimate should never be the sole basis for valuation. It's a starting point, not a conclusion. The algorithm cannot see the interior condition, recent renovations, or micro-location factors (backing to a commercial property, on a busy street, adjacent to a school). It relies on public records and nearby sales, so its accuracy depends on data density and market activity.
Zestimates are most useful for preliminary screening. When reviewing a list of potential acquisitions, the Zestimate quickly filters out properties where the numbers clearly don't work. For deals that pass initial screening, every serious valuation requires a manual CMA with hand-selected comps and condition adjustments.
When using the Zestimate for ARV estimation specifically, add a condition adjustment. A fully renovated property typically sells for 5–15% above Zestimate in most markets, since the algorithm tends to average condition across neighborhoods. Conversely, distressed properties often sell 10–25% below Zestimate, the opposite condition adjustment.
Pay attention to the Zestimate range, not just the point estimate. A $350,000 Zestimate with a range of $320,000–$380,000 tells you the algorithm has lower confidence than a $350,000 Zestimate with a range of $340,000–$360,000. Wide ranges typically indicate low comp density or significant outliers in nearby sales.
For rental analysis, Zillow's Rent Zestimate follows similar principles: useful for screening, insufficient for underwriting. Verify with current Zillow listings, Rentometer, and local property manager input before making decisions.
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