Towards the extreme - high mass buildings in temperate Australia.

In temperate Australia, traditional solar houses usually aim at 60-80% solar contribution to the heating and cooling of the building. In Northern Europe, however, in order to reduce heating energy requirements further, the approach has generally been to provide high levels of insulation combined with a comparatively air tight construction. Lund [ 1] has proposed that the thermal inertia of an extremely high mass house is another means of reducing heating and cooling energy requirements by smoothing out the seasonal variation in indoor temperature. This paper examines these two extremes: the high mass approach and high insulation approach. A number of variations in between are also examined, reducing material volumes down to traditional levels. Glazing levels (single, double and triple), and infiltration rates (medium, 0.5 ac/h and low, 0.1 ac/h) were also varied to allow for the Australian tendancy to interact more with outdoor spaces and regularly 'air out' buildings, even in winter. Embodied energy levels and reductions in recurrent energy requirements were combined in 60 year life cycle assessments to develop design guidelines for overall energy minimisation. The results of this work suggest that moderately massed, moderately insulated houses with low infiltration rates and double glazing work best in temperate Australian climates.