This modest California retreat evokes the spirit of local vernacular buildings and was designed to take maximum advantage of the site and climate to make the house comfortable while minimizing energy use and environmental impacts.
A single, large room contains living, dining, and kitchen areas on the south end, and is balanced by a bedroom and bathroom on the north end. A central, open breezeway integrates the outdoors into the heart of the house. The house provides a variety of indoor and outdoor living spaces that can be used in different ways as climatic conditions change over the course of the day or the year.
The chief strategy for saving energy was to keep the building cool during the long, hot summers without mechanical cooling. This was accomplished by employing natural ventilation, thermal mass, and superior insulation. The thin building section, the dogtrot, and placement of windows all maximize opportunities for natural ventilation. The interior plaster walls and concrete floor provide enough thermal mass to minimize temperature swings, and integrate well with the radiant heating system. Because this mass is cooled at night (just by opening the windows), the house remains cool through the hottest part of the day. The building envelope was developed using high performance, low-tech insulation—straw bales and cellulose insulation. Roof framing at 24 inches on center allowed for additional insulation and reduced thermal bridging.
Windows are wood, minimizing thermal bridging, and double-glazed with low-emissivity glazing. A highly efficient water heater provides radiant floor heating. These measures resulted in a design that keeps the building cool except during the hottest hours of the hottest days. The owners chose energy-efficient, low-water-use appliances.