I'm working up some plans to build a 16'x16' two story cabin next summer. The place is only accessible by foot and by snowmobile in the winter (so I'll be sledding all my materials out this winter). One old engineer told me that I should pour a wad of cement at the base and use sona tubes with Simpson bracket at the top. He said about 4 feet under grade would be sufficient.
The other day, I talked to a young engineer. He said that I should only need to use green (treated) 6"x6" posts that rest on 24"x24" treated wood bases (2x12s 2 layers thick, and criss-crossed). He said that I should only need to go 2 feet down!
The land is in Homer, and it's towards Caribou Hills, so It's colder than Homer proper, but still, it's no Fairbanks. There is crushed sandstone under about two feet of soil and sand. Pretty good drainage, although it seems to always be draining. Also there is a grade to the building site so one end will be about 6 feet up, and the other only about 2 feet up.
What type do you recommend?
Another question is, if I build a deck on the 16x16 structure, should I build it separate, or right onto the same beams that will hold my floor joists up?