The minimum down payment for a 1-unit investment property is 15% for conventional loans. However, it will come with mortgage insurance and higher rates. Make a 20% down payment to bring down costs. For a 2-4 unit home, the minimum down payment is 25%. If you are buying a 2-4 unit and can live in one of the units, you can use an FHA loan with as little as 3.5% down.