Research on household energy conservation often categorizes targeted behaviours by their behavioural attributes (e.g., savings, cost, frequency). The most common distinction in the literature divides behaviours as follows: (1) low-impact, low-cost, repetitive behaviours that result in a loss of comfort or curtailment behaviours and (2) high-impact, high-cost, infrequent behaviours that result in no loss of amenities or efficiency behaviours. However, such categorizations have often been ad hoc and two-dimensional (e.g., low-impact vs. high-impact, low-cost vs. high-cost). In contrast, we systematically assess a large range of household energy-saving behaviours (N=261) across nine attributes - energy savings, cost, frequency of performance, required skill level, observability, locus of decision, household function, home topography, and appliance topography. By clustering behaviours according to these attributes, we discern four clusters of energy-saving behaviours: family style, call an expert, household management and weekend project. We discuss the implications of these clusters for intervention design. (C) 2016 Elsevier Ltd. All rights reserved.