If you are going to live in a house for at least 10 years then there is no doubt a 15 year loan will save you money over the long haul (if you can afford it). But if you are looking for a short-term investment (7 years or less) there is no doubt that the 30 year loan is a better investment, keep in mind that the first 4-7 years of a loan paid back primarily goes towards interest. Therefore having a longer term loan will reduce the monthly payments reducing the interest paid on the principle.