We are currently designing an 1800 sq. ft. addition to an historic Joe Esherick house in the Berkeley Hills. When complete the addition and main house will together operate as a zero-net energy home.
The addition serves as sleeping quarters for the family and is connected to the main house via a Z-shaped communicating link-way. Sitting midway between the main house and the addition, within the to-be-restored Larry Halprin designed garden is a glass tea room. Bridges spanning from each of the two main structures to the tea room complete the link and allow surface runoff to flow freely from the uphill side of the site north. This link-way acts as a daytime heat sync in the winter months and a nighttime cold sync during the summer.
The addition is designed to be assembled from, factory fabricated, load bearing, metal wall and roof panels made from high recycled content galvanized steel studs. The panels, fabricated in Sonoma, will arrive on site as a complete assembly with windows, insulation, sheathing and a waterproofing membrane already installed. Later a set of matching cladding panels made from Machiche planks will be fastened to the wall panels. Machiche sliding louvers serve as both courtyard privacy screens and to protect the west facing bedrooms from excessive solar heat gain.
Special millwork utility walls, also fabricated off site help to demise the interior spaces. Pultruded fiberglass, low-e glazed, double pane windows with a suspended heat-mirror film (R-9) are specified throughout. The butterfly roof serves as part of a rainwater catchment system designed to both maintain the water level in the “alpine” reflecting pool and for landscape irrigation. To further conserve water, pumps on dedicated recirculating loops will ensure the timely and efficient delivery of hot water to all domestic fixtures.
A 5.0 kW south facing solar array on the eastern half of the roof will generate enough power for lighting, plug loads, operation of a heat recovery ventilator and an electric air-source heat pump with integrated refrigerant-to-water heat exchanger serving a hydronic radiant floor heating system.
