This house in the desert keeps itself cool and generates its own power
By Stu Robarts
July 9, 2014
A house built in the demanding environment of Alice Springs, Australia, has been honored by the Australian Institute of Architects (AIA). Dunn and Hillam's Desert House was designed to withstand the extreme desert conditions while remaining energy efficient. The AIA cited the project's "genuine sensibility to environmental management in this specific climate."
Dunn and Hillam was asked by its clients to design a house that would allow them to make the most of living in Alice Springs, taking into account its climate and spectacular scenery. The clients requested that the house engage with the surrounding landscape, that it provide multiple places to be use depending on the time of day and weather, and that it minimize energy usage.
In tackling the brief, Dunn and Hillam said it took an approach of "hardcore pragmatism and innovation, respect for the landscape and context and a belief in doing things better for the future." The house is cut into the rock and uses the thermal mass of the rock to regulate its internal temperature.
A fly-roof is employed to help reduce the internal temperature of the building. The fly-roof sits 600 mm (24 in) above the insulated roof, creating a pocket of warm air during the day. This creates a "thermal draw," helping to pull cool air up from the rock below into the enclosed central courtyard and creating the house's own micro-climate. The cool air can then be drawn into the building through low windows around the courtyard.
A hydronics system is also used as means of helping to regulate temperature. Slabs of flooring concrete are cooled using water that is pumped through them. During the winter, solar-heated water can be added into the system to warm the house if need be.
Dunn and Hillam explains that, as well as being heavily insulated, the Desert House has no thermal bridging. This means that the chance of cool air leaking out of the house (or warm leaking in) is minimized. Similarly, temperature in different sections of the house can be managed independently.
In addition to managing its temperature using low energy thermal processes, the house also generates its own electricity using a 5KW photovoltaic array. Rainwater tanks, meanwhile, are used to collect water for use in the hydronics system.
The Desert House has an area of 260 sq m (2,799 sq ft). Its temperature is regulated at 18-20ºC (64-68ºF).
Source: Dunn and Hillam