The Walls are made with SIP's. Translation: Structural Insulated Panel walls.
Manufactured by Panel Pro out of Keene, NH, the panels went up in less than a week's time.
Consisting of 2 layers of OSB (orientated strand board - a wood manufactured product similar to plywood) bonded either side to a 6" layer of rigid foam insulation. The panels come in large sheets, and are cut to size to fit together like a giant 3D jigsaw puzzle. Window openings are cut into the panels in the factory.