Someone wrote that these are manufactured by Tri_Steel and that is NOT correct. They are made by MBCI and Heritage buys that parts from diffrent suppliers. There is not a single person out there that knows more about ASH than I. I worked there, I bought a home from them, I live in a steel home, I built my own steel home, I have family that still works there today. They don't live in steel and thus they don't understand about steel. One of the best things you can do to prevent the cold from comming thru is to sheath the house in "WOOD" that's right dreaded wood. One of the house brothers did this a year or so ago when he built his own home. Now that dont tell you that when you buy, but that is a fact you can go to that bank with. But this is not his full time residence rather his weekend hunting lodge. You can build one faster than wood IF YOU HAVE THE TOOLS, AND THE EXPERIENCE TO WORK WITH STEEL. If not forget it!!! As others have pointed out most contractors with charge you more to work with steel. You also dont want to use a paper type of insulation. The steel forms condensation on the inside walls and you will develope mold like you have never seen if you do. Foam and only close cell foam will work. Open cell foam will hold mositure and then rust your home. They will always crack and pop day and night with the heating and cooling as well. The people who owned Heritage really really suck, but if you can live with the basic box desighn there is no house stronger than these.