A BRRRR deal fails at the refinance, not at the purchase. Five assumptions do the damage.
1. ARV
Use closed sales, not active listings, and cap your ARV at the highest defensible comp — not above it. An appraiser will not reward your finishes as much as you expect.
2. Rehab budget
Take your scope, add 15% contingency, then add the two line items everyone forgets: permits and holding costs during the delay you haven't planned for.
3. Rent
Market rent means signed leases in the last 90 days on comparable units, not asking rents on listing sites. Then underwrite 5–8% vacancy anyway.
4. Seasoning
Most lenders want 6–12 months of ownership before lending on the new appraised value. If your capital is committed elsewhere in month four, the deal is dead regardless of the spread.
5. DSCR
Run the debt-service coverage ratio at a rate 100 bps above today's quote. If it clears 1.20 there, the deal has room. If it clears only at today's rate, it doesn't.
The stress test
Model three cases: ARV down 10%, rehab up 20%, rent down 8%. If all three at once still leaves you cash-flow positive with capital returned in 18 months, it's a deal.
Run the numbers with the [Rental Investment Analysis](/rental-investment-analysis) tool.