The Cottle Home, a 3200 sf luxury home in the heart of Silicon Valley, is the first Certified Net Zero Energy new home in California and will produce all the energy required by its occupants to live and stay comfortable from solar energy systems mounted on its roof. This is possible because the building has been designed in cooperation with the US Dept. of Energy's Building America program dedicated to high performance building science and technology, and the home design meets the international Passive House standard which is so energy efficient that the building can be heated with a hair dryer.
Explore this web site and the One Sky Homes web site for more information about the Cottle Net Zero Energy home project and high performance building.
To achieve superior thermal performance, durability and protection from the elements our crawl space floor is a multi-layered assembly. First, the space was filled with 4 inches of gravel for drainage, followed by heavy duty polyethylene sheeting as a vapor barrier. The third layer is 3" thick expanded polystyrene (EPS) foam sheeting for insulation.
To protect the house from water vapor entering the crawlspace by evaporation of water contained in moist soil, we cover the gravel base with a high performance vapor barrier. The materials are made using virgin high density polyethylene . This bright yellow product is called StegoWrap. It's a tough 10 mils thick and very puncture resistant.
As designers and builders of high-performance homes, we believe in buildings that will remain durable over a long time (like 100 years or more at a minimum). Persistent moisture on wood will eventually lead to rot and failure of joists, sills and posts. Moisture also creates an ideal environment for mold, mildew and fungus which causes poor indoor air quality. Keeping everything dry is the single most important element of durable, healthy buildings.
A copper termite shield is installed around the entire foundation. It may be expensive now but a good investment when compared to the damage termites can cost a homeowner over the lifetime of the house.
By using Insulating Concrete Forms (ICF's), reinforced concrete is sandwiched between two layers of lightweight insulating EPS foam. The wall that is created provides a combination of air tightness, strength, sound attenuation, insulation and mass.