Decide as a couple whether to save for a 10% or 20% down payment on the house over 7 years. Whether you decide on 10% or 20% for the down payment, remember to add the 2% for closing costs. After you make that decision, decide on an investment strategy and a monthly amount of savings. You may use any combinations of investments in accumulating your down payment savings accounts, money market accounts, stocks, bonds, or any mutual funds, weighing risk and reward. Use a reasonable (verifiable) rate of return for investments in stocks or stock mutual funds; use a 2% rate of return for any investments other than stock.