We don't know much about the rest of your situation so this can only be general. You said 'add a home'. Is this a second home? I think you're single, is that right? How much your mortgage deduction would benefit you depends on your filing status(i.e. standard deduction amount) and your tax bracket but will be only a part of the interest you pay. Equity in a home isn't liquid. Do you have 6 months or more of living expenses already available? Is your job relatively secure? If you have credit card or other expensive debt, paying that off would benefit you more. People's situation changes over time, even in a short time. As a general statement, I think I'd put down 20-25% and take out a 15 year mortgage at today's rates to keep some flexibility. You can always start paying additional in a year or 2 and pay it off in 10 years if things are going well. Invest some of the rest longer term, keep some liquid depending on how much liquid assets you already have. You could use some of this to boost your retirement saving rate which would also reduce your taxable income. Why do you need the investment to be guaranteed? Is that because you can't financially withstand a short term downturn? In that case, I wouldn't tie up all the money in the house either.