The Role of Thermal Mass in the Sustainable Design of Australian Housing

There is an increasing worldwide interest in sustainability in all of its forms, and in particular the sustainable design of housing. In Australia this has been reflected in regulations which require new housing to satisfy various sustainability requirements, particularly in relation to energy efficiency and water consumption. Traditionally house design in Australia has been governed by aesthetic and economic considerations with little attention being given to factors such as energy performance. A range of veneer and cavity walling systems are available, but solar-passive design principles, taking advantage of the thermal mass of heavy walling, are not widely used. As a result, many houses use artificial heating and cooling to provide internal thermal comfort, with no attempt in the design to optimise the thermal performance of the build ing. Since this operational energy far outweighs the embodied energy of the materials, operational performance becomes a key factor in the design of a sustainable housing system. In this context, the more effective use of the thermal mass inherent in heavy walling such as brickwork has an important role to play in improving thermal performance. Some of the findings of a major on-going research project at the University of Newcastle focussing on this area are presented here.