Metal walls also cause condensation. Here's a good reference: http://www.tincancabin.com/

Building a 3 container cabin I believe wound up costing the guy $25,000

I've been thinking of making a tin-can-cabin, some sort of summer-vacation spot but I can't imagine trying to make a all-year-livable space in new york with containers. May as well buy an old building and pay to clean out all the asbestos.