What should I watch out for?

The most common pitfall on a two-family purchase is discovering after closing that the second unit was never legally permitted, which can affect financing, insurance, and the rental income you were counting on. Deferred maintenance hidden behind fresh paint, tenants with leases that do not transfer cleanly, and utilities that are not separately metered are the next most common surprises. A thorough inspection and a review of permit history before you write an offer catch most of these early. Joel Boss walks every two-family buyer through this checklist first.