It depends on why you are asking. If it is a condition of a contract, the contract will specify. If it is a condition of financing, the program will specify, etc. You will need to check with the specific guidelines with regard to the specific owner occupancy stipulation. As a general speculation, it will be as little as one to two years, or as long as 6+ years, depending, to avoid penalty and/or interest. Check with your agent, contract, banker, accountant or attorney as needed.