"Primatempra," House for Jim Pottenger & Family
Pacifica, California USA
Owner: Mr. Jim Pottenger
Location: Pacifica, California USA
Date: Original concept: 1990 (Oakland, California) Adapted concept: 1995 (Pacifica, California)
Square Footage: 1800 square feet
Construction Materials: Insteel spray-on concrete panels, glass, ferro-concrete and interior finishing wood.
Special features: Partial underground design with built-in retaining wall system, completely termite-proof, fire and water-proof, extremely earthquake resistent, circular plan design, roof garden and passive solar heating.
Owner Requirements: Create a unique structure, on a difficult property, whose design addresses the property issues and utilizes as much of the vista and natural light as possible. The house should be comfortable and imaginative.
Ecological Requirements: Be sensitive to the ecology of the site and create a living environment that is healthy and joyful.
General Background of the Project: This design was originally conceived in 1990 for a family of three in Oakland, California. The design was permitted and ready to build but due to sudden difficulty in the family's circumstances the project was abandoned. In 1995, Jim Pottenger a health-care worker and his family, saw a television program featuring featuring the work of Eugene Tsui and Tsui Design and Research, Inc., in San Francisco. They liked what they saw and we were contacted. During the initial meeting Jim Pottenger described his many likes and dislikes. He wanted something unique and affordable. His ideas included various kinds of domes and spheres all curvilinear in nature. As we talked further there were many possibilities developed.
Initially the Pottengers were going to raise their house and build on their own existing foundation. Eventually though, Jim Pottenger chose to purchase another site not far from their present house in the hills overlooking the Pacific Ocean. This site was steep with difficult soil conditions. After discussing the situation with their soils engineer we developed an idea that satisfied all concerned. That is, to place the structure into the hill like a vertical tube partially buried into the ground with its west-facing side open. This allowed minimum use of piers to reach the stable bedrock layer below. Bedrooms would then be placed at the lower levels and the more active public spaces situated at the grade level, the roof garden level rising one story above.
As the building began to take shape more clearly it became apparent that it was similiar to the design of a residence that had been developed almost five years before but was not built. Mr. Pottenger wanted this project to be extremely economical so I suggested that we might adapt a previously designed building to this new site with the understanding that the requirements of the 1990 version and the 1995 adaptation were virtually identical. By adapting an existing design we could make modifications by computer very quickly thus saving time and cost. This was a pleasant surprise for the owners and they decided it made good sense.
In structure the house resembles the tubular structure of the caddis fly larvae or certain species of wasp nests. The tubular structure is very stable and strong in its ability to resist and dissipate external stresses pushing on it. In this case, the soil surrounding the house will produce a great deal of compression and overturn. The tubular design acts as a unified body simultaneously resisting pressure and overturn as it is anchored into the bedrock four feet below. The soil cover also acts as insulation and a cooling source (underground temperture is consistently approximetly 60 degrees fahrenheit). A non-mechanical venting and heating system is established through the orientation of the house and its partially underground placement.