Observation on the NL/Bigfoot Clamshell Design

I would rate construction methods as 1) fiberglass clamshell,2) Styrofoam sandwich with aluminum framing, 3) Styrofoam sandwich with wood framing, and 4) the good? old stick and tin. Ease of repair would have a very different order. I shied away from a BF in my price range as interior repair, yes, the roof can leak, would be too much work.