$71k of rehab, then I learned my exit kills the 3.5% loan
Took over a 1958 ranch at $214k balance, 3.5%, 24 years left, PITI $1,498. Seller wanted $8k and out. House was rough, not unlivable. My plan was standard for me: put $45k in, rent it at $2,200, refinance in a year to pull the rehab money back out and keep going.
Scope crept to $71k because the panel was a 1960s fuse box and the sewer lateral had a belly under the driveway. That part I own, that's my job.
The part I did not think through is that a refinance pays off the existing loan. Obvious when written down. I had been telling myself "refi" as an exit for months without noticing that my exit destroys the only asset in the deal. Every quote I got was 7.25% to 7.6%, which turns $1,498 into roughly $2,050 at the same balance and more if I pull cash. So the choice was leave $71k of my money buried in a house at a payment that works, or refinance and hand back the rate that made the deal.
I left the money in. Return on the total basis is about 5.9% cash on cash, which is not what I do this for. Cost me a year of working capital and one deal I couldn't fund.
What I'd change: fund rehab on a sub-to with money that has an exit that doesn't touch the first lien, and decide that before the deed moves, not after the drywall.