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To move to holistic indoor environmental quality (IEQ) assessment methods of residential building performance in Australia, a relevant evidence base on the comfort behaviour and preferences of contemporary households is needed. A lack of information on the environmental conditions, behaviour and preferences relevant to dwellings in Australia’s hot humid climates has been revealed as an area of ongoing policy and research interest. This paper explores the cooling practices of households living in predominantly naturally ventilated dwellings in Darwin, the Northern Territory through a survey of behaviour, preferences and dwelling construction (n = 102) and a 12-month longitudinal thermal comfort study in 20 houses (n = 2535). The results show that these households employ a range of adaptive behaviours in response to warm and hot conditions. The houses were almost always naturally ventilated, with the assistance of ceiling fans for approximately 50% of the time. The limited use of air-conditioning in these houses is more strongly associated with indoor humidity levels than temperature. These patterns of comfort behaviour provide a basis for the enhancement of building simulation models for the performance assessment of dwellings in naturally ventilated mode in hot humid climates in Australia. [ABSTRACT FROM AUTHOR]

In assessing the energy efficiency of a house design, particularly methods incorporating building performance simulation, assumptions are made about how the occupants operate the building. Often these assumptions are standardised to simplify the assessment process with the intention of enabling a straight forward comparison between designs. Assessment of performance using standardised operations may pose a disadvantage to house designs that are intended for households who are likely to operate the house outside of the assumed norm. This paper examines occupant behaviour in low energy houses in the context of the Australian regulatory house energy rating scheme and, using simulation, demonstrates the impact of alternative occupancy settings on the validity of the predicted house energy rating. The results clearly show that current occupant assumptions within the scheme fail to adequately reflect actual heating and cooling practices in low energy dwellings and, as such, overestimate energy consumption within these households. Based on these results it is suggested that, for equitable assessment of these households, settings within the simulation engine used for assessment must be modified to align with actual user behaviour. [ABSTRACT FROM AUTHOR]