Colin, depending on how long you have owned your primary duplex and how much equity you have built up, you may be able to cash out refinance your current home and invest that money toward the next place? Just make sure your new refinance payment still allows you to cash flow and your debt to income ratio (after the new purchase) will be under 42%. I am new, have only done one rental deal, but that is how I did it. Interest rates are much lower now than when I initially purchased so my original mortgage payment didn't go up much even after the cash out refinance. If you financed your primary with fha and have been there a year and are willing to move, you might refinance the first into conventional, pull cash out and finance your second through fha (if you are willing to move into the second for at least a year). The costs of doing the loans may be prohibitive if you don't already have significant equity built up. Again, I am new, so definitely not an expert but I wanted to share the options I have considered :) Best wishes!