An overnight fire that consumed the Owner’s previous weekend/guest house provided the opportunity to replace it with the least ecological impact. The surviving concrete slab determined the 1280 square foot footprint, with 1000 square feet conditioned. Concentrating the plumbing in the northeast corner over an existing 5’ x 19’ slab offset eliminated cutting and trenching the slab. Cargo containers (two 20’ and one 40’ long) configured in a “U” provide a series of compact spaces and define a generous living room and a south-facing porch.
Two shed roofs reflect the plan geometry, create hierarchically appropriate volumes, and induce passive north light and stack ventilation through clerestory windows. The pitch of the larger, south-facing slope is optimally designed for a (future) large photovoltaic array. (A detached one-car carport carries eight 210 watt PV panels that can generate 1.7 kilowatt of electricity for an electric car, local consumption at the house, and/or sale back to the grid.) Attic space above the 20’ containers accommodates mechanical equipment and provides a storage loft.
Vegetable-based foam insulation at the roofs, walls, and floors, along with optimally-positioned high-efficiency windows and doors, yield a tight building envelope. The vertical well, closed loop geothermal heat pump system also preheats domestic water year-round into a 30-gallon storage tank, reducing load on the propane-fired demand water heater. Since the project budget precluded constructing a cistern, only some of the roof’s rainwater yield of 600 gallons per inch of rainfall goes into the modest rain barrel used for house plants and to suggest what is possible.
The Container House has an audited Home Energy Rating System (HERS) score of 38, consuming 62% less energy than a HERS reference home. (Eighty-five or less can earn an Energy Star Rating.) It earned a NAHB Model Green Home score of 508, a Gold Rating, equivalent to a LEED-H Gold.