In October 2002 my husband and teenage sons added a full story to our ranch house to make it a two story house. We had 10 kids and it was either add on or move. We choose to add on. It involved taking off the roof, adding floor joists and everything else you can imagine. I agree with Happygirls three points. It is doable and I cannot imagine not having the space we have now. My dh and sons did all the work, except installing a new, bigger electrical panel because you needed to be a licsensed eletrician for that. He did do all the plumbing and other electrical work by taking tests with the county and getting permission. All of the inspections that we had to have went very well, except the one for the electrical panel!!! The inspectors were very impressed with my dh's work. There were a few accidents, minor, and it was stressful. It took about 2 1/2 years which wasn't bad considering my dh worked a full time job at the same time. He did use his two weeks vacation those years doing nothing but working constantly.