All, I’m about one year out from a new garage project (detached, built of native rough lumber; should be fun), and about 2+ years out from a new house build. 

The house plans are still developing, but it’s looking like roughly 2400 sq ft (I have a big family), 2 stories, planning R40 walls using either a double stud assembly or 2×6 and a thick layer of insulation outside the sheathing.

For the house (and possibly the garage) I am hoping to build using a frost protected shallow foundation. One reason is cost. A much bigger reason is that I live in the East Bay of Rhode Island and (if you know the area) there is a lot of concern about rising sea levels and hurricanes. Plus my land is just soggy. A shallow foundation should avoid some of the water management and flooding concerns we are bound to face with a basement, or even a crawl space.

Are FPSFs code in Rhode Island? I just looked at the code (R403.3) and it states that “The use of frost-protected shallow foundations shall be limited to one-story buildings a maximum of 16 feet from average grade to topmost part of main roof.” 

I’m scratching my head here. I thought FHB’s project house in Rhode Island used a FPSF, and it was becoming increasingly common. Am I misreading the code? Any inspectors or industry pros care to chime in?