Materials for the house are strong, insulative, and lightweight. The walls provide significant supports for the home, but do not exceed the trailer load capacity of 7000lbs. To sufficiently support the house, the materials withstand the weight of the larger items such as solar panels, batteries, and intermediate water tanks.
The following is an excerpt concerning material decisions for selected components. For more information, please consult our full report, which is available for download here.
Roof - Organic Composite Materials
The roof material affects the solar panels, the rainwater collection system, and the structural component of the home. The material must be compatible with solar panel mounts and must support the weight of the solar panels. The material also must be appropriate for collecting rainwater (see Plumbing section for more information).
Many common materials are deemed unsafe for rainwater collection, due to their tendency to release chemicals into the water. The roofing material, Enviroshake, is composed of 95% recovered plastic. The material is a composite blend of post industrial plastic(s), recycled rubber elastomers, and cellulosic fiber materials. It is deemed safe for our roof pitch and rainwater collection.
We will be using bamboo flooring It is a renewable
resource, which takes only four years to fully mature and weighs, less than
3lbs a square foot on average. (Timber on average takes 25 to 50 years to
Windows - Low-E
Windows are located above the kitchen counter, next to the loft bed, and on the south and west sides of the home. All of these windows create an illusion of space, without compromising insulation.
The windows are energy star rated widows with layer of Low-Emittance coating and argon gas filling between the panes. Low-E coating allows light to pass through the window, without allowing an exchange of radiant heat. The coating aids in insulation of the home.
These windows’ R value ranges 2-6. While triple paned windows increase the R value, the costs of additional panel do not outweigh the benefits. Honeycombed shades provide room darkening and insulating properties.
Insulation - Icynene
Insulation is critical to maintain a livable temperature within the small home. The home's size gives it a small thermal mass, or resistance to changes in temperature. Moreover, this off-grid house relies on only a small wood-burning fireplace and a few ventilation windows to maintain the temperature inside. A more powerful, electric powered heating and cooling system is infeasible. Therefore, the burden of temperature moderation falls primarily on the home's insulation.Icynene spray foam insulation is up to the task. Sprayed as a thin liquid, the product rapidly expands to 100 times its initial size. Once installed, this product will provide a high resistance to heat loss as well as substantial sound dampening. But unlike other insulation materials, this tightly packed foam provides a complete air barrier system, preventing air from moving through the walls and ceiling. And unlike polyurethane spray foam, Icynene neither contains environmentally damaging chemicals nor requires any such chemical as a propellant during installation.