The house will be 2 story, approx 4000sqft. I recently watched a house go up in my neighborhood that used steel I beams instead of pressure treated wood for long runs. The had a crew come out with a crane and put 4 beams sticking straight up, then 4 horizonal beams connecting the 4 vertical. Then the foundation was poured around the beams that were 5 or 6 feet into the ground. They then used wood for the rest of the frame.
I like the idea of using all steel (no shrinkage, less bugs, no termites)... I'm just thinking it is a lot more expensive and it seems like a pain for running electrical, plumbing, HVAC, and other wiring.