landlord 101

your age will make a big difference here as the younger you are the better. There are also a lot of tax advantages to doing this. If you must do a mortgage try and make sure your payment is 1/2 the rent. You can also look into the foreclosed HUD homes in your area. You will probably not qualify for a HUD unless it has already been foreclosed on. (if that is still a policy. We did this a long time ago). The interest on a mortgage will defeat the purpose if you are going dollar for dollar unless you have a good chunk of down money. Thats all I have good luck. This can be a retirement enhancement if you play your cards right.
im 41, but i dont think you're looking at this right

the mortgage would go on the place that we own free and clear now
it would only free up the equity that we have in the house now, to build a new one