ATTOM reported 2025 was the lowest-ROI flipping year since 2008. The typical flip netted $65,981 gross profit at 25.5% ROI. The 30–40% of flips that lost money usually failed the same four ways. Catch these before you submit the offer and you eliminate most of the downside.
Failure 1: ARV was wrong
You modeled $310,000 because three renovated comps sold at $305–$320k. But your comps were 0.4 mile away in a slightly better school district. Your appraiser pulled the closer comps that sold for $275–$295k. ARV reality = $285k. You priced $25,000 of profit that never existed.
How to catch it
- Use three comp tiers: optimistic (top 25%), median, conservative (bottom 25%)
- Always underwrite to the conservative ARV
- Verify your comps' school boundaries, transit, and block-level condition match yours
- If pricing is sensitive to a single $310k comp, you don't have a deal
Failure 2: Rehab budget blew up
You budgeted $58k for a mid-tier rehab. Demo started, and the kitchen floor was sagging, the electrical panel was undersized, and the basement had a water issue. Real spend: $79k. That $21k overrun ate your entire profit margin.
How to catch it
- Use 12–15% contingency on vintage stock, not 8%
- Get an inspector on the property BEFORE you finalize the bid — $400 saves five-figure surprises
- Stress-test the deal at +30% rehab. If it still works, you have margin. If it doesn't, walk.
Failure 3: Hold time blew out
You planned 4 months hold. Materials shortage delayed cabinets 5 weeks. Your contractor moved you down the priority list. You went on the market 7 months in. At 11% hard money on $200k, every extra month is ~$1,850 in interest plus property tax, insurance, utilities, debt service. Three extra months = $7,000+ in extra carry.
How to catch it
- Underwrite to a 6-month hold even if the contractor promises 4
- Add a 3-month worst-case stress test
- Order long-lead items (cabinets, windows, custom millwork) at close, not at month 2
Failure 4: Sale costs were underestimated
You budgeted 6% agent commission and $3,000 in closing costs. Reality on a Chicago flip: 5–6% commission + 1% Chicago transfer tax (paid by buyer below $1M, by seller above) + title insurance + recording + escrow + concession on inspection findings. Total: often 8–10% of sale price. On a $310k flip, that's $25k–$31k vs the $21,600 you budgeted.
How to catch it
- Underwrite sale costs at 9% minimum on Chicago flips
- Add a $5,000 line for "post-inspection concessions" — almost every deal has them
- Verify the Chicago transfer tax obligation based on your sale price
The two-number rule
If after stress-testing ARV down 7%, rehab up 30%, hold +3 months, and sale costs at 9%, your projected profit is still positive and your ROI is still >15% annualized — you have a real deal. If any of those stress tests turns the deal negative, you don't.
How Prop-Folio helps
Prop-Folio's Fix & Flip calculator surfaces ARV, rehab, hold, and sale cost assumptions on separate cards so you can stress-test each one independently. Adjust any input and the projected profit, ROI, ROI annualized, and Deal Score update instantly.
Related: Cook County flip calculator · Why most rehab budgets underestimate by 30% · Rookie investor mistakes