I suggest that you look into a "pole building" before you make your decision. I live in the mountains of North Carolina where the weather swings from one extreme to another. I built my hobby shop two years ago and it works really well for me. It is 120 X 40 clear span with a 10 X 80 foot shed on one side and a 10 X 30 foot shed on the other. The truss joist height is 13 feet. It has one 10 X 10 drive in door, two people doors and several windows. It has a concrete floor and is insulated well enough to make it "workable" in zero degree weather with forty mile an hour winds. We have experienced winds of over 100 MPH on the ridge and no damage was sustained. I have had no water leaks or any issues of any kind so far. The building technique is to grade the land, sink 6 X 6 pressure treated posts, construct a wooden framework, drape that framework with insulation, skin the whole thing with steel and then pour the concrete floor. The building cost was $45,000 on my graded lot. I did the installation of a heating system and a rest room and wired it myself, but that was a piece of cake. The finished product looks exactly like a prefab steel building. If you are interested in investigating this type of building let me know and I'll get more information to you. Cheers, Jack