I've got a little money available (about $20,000) and would like to get some ideas of some improvements I can make in my 1962 ranch. It is long and narrow so adding a room/space would be great but I don't know how to estimate costs. I don't need to remodel any bathrooms or kitchens, am thinking maybe enclosing back porch, converting 2-car garage to living space, etc but have not idea how to cost these projects. Can anyone help? Thanks in advance.

My first thought is insulation upgrade. This is something that can earn you a tax rebate and start saving on utility bills immediately with increasing returns over the years as energy costs rise. Those returns can be plowed back into other iomprovements.

See a LEED inspector to evaluate your house.

Excellence is its own reward!