Targeting 'behavers' rather than behaviours: A 'subject-oriented' approach for reducing space heating rebound effects in low energy dwellings

A common strategy to reduce energy consumption and CO2 emissions is retrofitting residential buildings to high thermal standards. But households in retrofitted homes often consume more space heating energy than expected, thus frustrating climate and energy goals. Most interventions to mitigate this focus on energy-inefficient 'behaviours', and assume that identifying the causes of these behaviours can deliver interventions that change consumption patterns and habits across large groups of consumers. A detailed investigation of sensor data from 60 retrofitted apartments served as a testing ground for an alternative or supplementary approach: targeting 'behavers' rather than 'behaviours'. Consumption patterns supported the division of households into 'light', 'medium' and 'heavy' consumers, each showing a normally distributed picture of consumption. Heavy consumers (23% of households) consumed 52% of the space heating energy, medium consumers (57% of households) consumed 45% and light consumers (20% of households) consumed 3%. Among both heavy and medium cohorts the data indicates very stable patterns of consumption across time, deeply entwined with routines and with the physical fabric of the indoor environment, and therefore very difficult to change. Since the heavy cohort is a small minority of households that consumes around half the total energy, it could be cost-effective to target this group specifically rather than aim interventions at consumers in general. Other datasets of low energy homes suggest that a similar heuristic could be appropriate. (C) 2013 Elsevier B.V. All rights reserved.