Owner-occupant financing means a loan priced and underwritten on the assumption that you will live in the property as your primary home. The differences from an investor loan come in a few places.
Down payment is the big one. An FHA loan can go as low as 3.5 percent down on a property of one to four units, as long as you occupy one of them. A VA loan can go to zero down for eligible veterans. Conventional owner-occupied programs also have low-down options. An investor buying the same fourplex with no intention of living there is generally looking at a much larger down payment.
On rate, the person who told you it's the same rate with different insurance is closer than the one who said rate is identical. Lenders typically price investment property loans with an add-on because the default risk is higher, so the quoted rate on an owner-occupied loan is usually lower for the same borrower. FHA loans carry mortgage insurance premiums that can last the life of the loan, which is a real cost you have to put in the math. Get both quotes in writing from your lender and compare the total monthly payment, not the headline rate.
Occupancy is not forever. The commitment is usually expressed as an intent to occupy for a period, commonly around a year, stated in the loan documents you sign. Read the occupancy clause in your own note rather than trusting a number from a forum, because programs differ and lenders add their own language.
The thing that catches people is the appraisal. On a two-to-four-unit purchase the appraiser also produces a rent schedule, and that number, not your optimistic estimate, is what the lender uses.
