Adelaide Residence, Santa Monica, CA, USA
After almost 15 years and considering different locations and designs, Frank O. Gehry has now completed and moved into his new private home in Santa Monica. It is a clear affirmation of Frank O. Gehry's commitment to sustainable buildings.
The climate concept, which was explicitly designed to operate without traditional air-conditioning, is based on wind-driven cross ventilation to ensure low emissions. Since the building is targeting to become the first zero-energy house in Santa Monica, the Santa Monica authorities allowed the building to be built three meters higher than the specified construction line based on the airflow analysis, so that it could use the best wind exposure for the natural ventilation. A big advantage of this location aside from the Californian sun is the constant wind from the Pacific Ocean to the West, cool in summer and rather warm in winter, but generally dry.
The natural ventilation via motorized facade flaps is controlled by a sensor-based measurement of temperatures and the air quality and also allows night air cooling. Insect screens had to be taken into account in the dimensioning of the openings. The two floors of the main building are an open-air space, which reaches up to the roof tops to achieve a maximum chimney and wind suction effect as a driving force for the ventilation. During use, it became apparent that the servomotors of the ventilation flaps cause disturbing noises and must be coordinated with the rest periods in the house.
Solar gains are limited by roof overhangs, a selective double glazing and a motorized freely ventilated interior shading with a room-side low-e coating. The view of the Pacific Ocean should remain as unobstructed as possible, which was achieved by a residual transparency of the solar shading even when closed. In addition, works of art in the house had to be protected from direct sunlight. The cross-ventilation driven by the wind and supported by the open construction via the chimney effect dissipates external and internal heat loads via the gable openings.
From nine closed geothermal probes, each 92 m deep, a highly effective reversible heat pump supplies heat or cold as required. A large part of the waste heat from the heat pump is used for hot water preparation and pool heating in cooling mode. The stone floor with underfloor heating and cooling ensures the basic conditioning: its relatively high cooling and low heating temperatures (17 / 27° C) result in a high efficiency of the heat pump. For the individual temperature control of rooms, a noiseless gravity air circulation system in cavity walls drives the cooling, dehumidification and heating, and allows to stay with the natural ventilation even at higher outside humidity. Cool and dry air collects near the floor, while moist and warm air rises to the top. 7 m² of highly efficient thermal solar collector surface support the hot water production. Photovoltaic modules on the roof of the guest house, 65 m² at present, provide energy for the targeted zero energy balance.
The house is equipped with a complex building control system with data acquisition. This enables the building behavior to be documented and evaluated online as well as remotely. After the first year of operation, the evaluations show several optimization potentials. For example, the effectiveness of the thermal buffer storage could be increased by adapting the control system, and a change in the piping system, which makes direct free cooling from the geothermal system possible.
After a period of coordination with a team of architects from Gehry Partners on site and a prompt evaluation in Stuttgart, the thermal behavior of the new Gehry residential building offers a high level of user comfort and meets the individual requirements of the residents.