Cedar slats mark the facade of Floating House, Doug and Becca Worple's lake house in Ontario. The architects, MOS, chose materials and shapes that wouldn’t stand out. “They’re really simple, almost Platonic forms,” principal Michael Meredith says. The modest cabin has boat, a gabled roof and a cladding of untreated cedar, a material that shows up on docks and homes along Georgian Bay. “Allowing the buildings to weather seems the right thing to do,” Sample says. And it’s ready for winter: Sliding barn doors seal the place up as an impenetrable box.