The local lumberyard provided more than just building supplies for this Eastern Long Island, N.Y., house. The building’s structural frame incorporates components of the cantilevered rack systems found in lumberyards and big-box home centers. Prefabricated steel uprights, bolted to the concrete foundation, serve as columns. Adjustable brackets and arms of various sizes—more standard pieces—support shelving, cabinets, and an upper-level gallery floor. Architect Paul Masi calls this experiment in shopping-cart engineering “very liberating. You can have these wide, open spans. The house becomes very versatile and adjustable.” Painted black to contrast with the rough-sawn cedar plywood infill panels, the structural hardware also provides visual punctuation, as at this doorway, from the main room to the stair landing. Cantilevered arms suspend two treads of rough-sawn cedar above the floor. The cedar-decked landing and stair float behind a screen of rough cedar slats.