The #1 ARV mistake that quietly kills fix-and-flip margins
The #1 mistake fix-and-flip investors make on ARV (and how to catch it before you close)
Most investors calculate ARV off 3-5 "comparable" sales pulled from Zillow or their agent's MLS search — but comps within the last 90 days in a fast-moving market can already be stale by 8-12%. That gap is the difference between a deal that cash flows and one that eats your contingency budget.
Here's the underwriting checklist we baked into DealScope AI's ARV scanner:
1. Radius isn't enough — filter by lot size and square footage variance (±15%). A comp 0.3 miles away with a 400 sq ft difference will skew your number more than a comp 0.8 miles away with a near-identical footprint.
2. Weight recency over proximity. A sale from 20 days ago 1 mile out is more predictive than a sale from 85 days ago next door, especially in markets with >5% YoY appreciation.
3. Strip out non-arms-length sales. Foreclosures, family transfers, and flips-to-flips distort the comp set — exclude them or your ARV skews low.
4. Cross-check renovation scope against comp condition, not just price. A comp that sold "renovated" but your target is a gut job needs a repair-cost-adjusted ARV, not a straight comp average.
5. Run a rental-exit ARV in parallel to your flip-exit ARV. If the flip market cools mid-project, knowing your cash-flow-positive rental floor gives you a real exit instead of a fire sale.
If you want a second read on a deal you're underwriting right now, drop the address in the chat — happy to compare notes.
