Galvanized Steel will not crack, shrink, splinter, creep, split, warp, swell or rot. Steel is impervious to termites and wood destroying insects.
A single story house using cold-formed steel for the wall and roof framing has approximately 16kg of steel per square foot of floor space. A two-story house has approximately 20kg of steel per square foot of floor space.
Yes, you can build buildings up to 4 stories tall.