It’s not easy to buy a first home, so here’s a suggestion that may be surprising: Instead of buying one residence, buy several. What I’m suggesting has nothing to do with late night infomercials or books that promise fast and easy wealth from real estate. Instead, many first-time buyers can benefit from an interesting quirk in the mortgage system. When you hear people talk about “real estate financing” they generally divide mortgages into two categories; loans for owner-occupants and more expensive and tougher loans for investors. “Investment financing” is for buyers who do not physically reside at a property. “Owner-occupant” loans are for homes, the places where we stay at night, the phone rings and the car are parked. But there’s a wrinkle: Owner-occupant financing with little down and low rates is typically available for the purchase of more than a single-family house. Normally you can get owner-occupant financing for properties with one-to-four units as long as you use one as...