The Sunergy Cabin was designed to house two occupants year round with the goal of using sustainable/natural products that are locally available, while reducing the amount of fuel required for supplemental heating. This cabin uses a number of unique features to accomplish the goal. It is a load bearing straw bale cabin with a metal rain screen. The metal rain screen allows the bales to breathe while still protecting them from the elements. Most straw bale homes call for a good "hat" (roof) and "boots" (foundation) to protect them from moisture. I don't know about you but I wouldn't go out in a rain storm in hats and boots, I would put on a rain jacket as well. In this case the jacket is the metal rain screen. Passive solar design practices were used throughout the design of the cabin such as southern orientation, overhangs, efficient building envelope, operable windows and reduction of thermal bridging. Passive solar energy is estimated to provide 20-30% of the heating demand.
The cabin has a 3 foot overhang that shades the home in the summer but still allows for the winter sun to penetrate into the building; this reduces the amount of energy needed for heating and cooling. The innovative foundation is constructed out of adobe and an extruded insulation foundation tray. The foundation tray dramatically reduces the amount of heat lost to the ground while using natural/local material for structure. The thermal mass helps store and regulate heat to provide optimal comfort. Some concrete could be used to increase the strength of the slab. Because the heat loss of the cabin is minimal a small homemade rocket stove can be used to heat the cabin. The cabin will be air tight, so an insulated cold air intake must be used. The rocket stove could burn deadfall and/or homemade cellulose bricks from scrap paper/cardboard. If softwood/hardwood is used then the cabin will need under half a cord a year for heating. A 120W PV panel provides electricity for the 12V DC 7W LED lights and laptops (with the use of a small inverter). Burning local deadfall and using PV for electricity means the Sunergy Cabin is off grid, net -zero site energy and carbon neutral.
The Sunergy Cabin was designed to incorporate as much local/natural materials as possible while still keeping energy demands as low as possible. The straw bales, plaster and adobe can all be found in the local area, which reduces the embodied energy of the cabin. Cellulose insulation used in the roof is 87% recycled and is manufactured in Canada. A rainwater harvesting system provides water for irrigation uses.
Thanks for taking the time to learn about my cabin design, I hope you enjoyed!