Rented three rooms in my own house, collected two thirds of plan
I bought a four bedroom on the edge of a state school town, $340k, 5 percent down on an owner-occupied conventional loan. Payment with taxes and insurance came to $2,650. The plan was three rooms at $750, so $2,250 of the payment covered and I pay $400 to live somewhere I own. Year one is done and I averaged $1,540 a month collected, so I paid closer to $1,100 a month, which is more than the apartment I left.
Where it went wrong, in order. First room I filled with a friend, no written lease, no deposit, month to month by handshake. He left in month five owing $1,500 and I have no realistic way to collect it. That room sat empty four months because I started looking in November and nobody moves in November here. Second, I advertised rent as utilities included and never metered anything. Utilities ran $340 a month across the year, up to $430 in July with the AC going constantly, and that came straight out of the rent I was counting. Third, I furnished the common areas and two of the bedrooms, $4,200 on a credit card, which I never put in the original math at all.
What I'd do differently: a written lease per room with a deposit held the way my state requires, and I'd confirm those deposit rules before taking a dollar since they vary by state. No friends. Budget each room at nine months paid, not twelve. Either sub-meter or cap utilities in the lease. I'm keeping the house, the second year is already better, but the first year cost me about $8,400 against my own numbers.