Behavior, Energy and Climate Change Conference

Our behaviour in our homes can seriously affect the associated carbon dioxide (CO₂) emissions. In the UK, space-heating accounts for nearly 60% of domestic energy consumption and 27% of total CO₂ emissions come from our homes. Regrettably, low-energy building design does not guarantee low-energy performance. Controls systems, in particular heating controls, are often too complex for users to programme. This study uses real-world data from buildings, observational data from users and energy modelling to establish why people have difficulty using their control systems, and the potential resultant energy impacts.

Users were asked to programme an example heating profile for a week using three different control interfaces. Prior to attempting this task there was a preconception amongst users that they would be unable to complete it. Controls were found to exclude users due to the cognitive demands placed on them. A key observation was that five of the twenty-four users made a mistake in the programming process, which meant that the heating temperature was not reduced at the end of the heating period. This could potentially result in accidental heating throughout the day and night, unbeknown to the users.

Modelling this observation showed an increase in heating energy consumption of 14.5% compared to energy consumption associated with successfully programming the example heating profile. The modelling results showed that successful programming of the profile consumed less energy (in two of the three scenarios) than the default settings of the heating controls. Increasing the sense of perceived control users have over their environment may enable them to use less heat energy. By designing controls so that pro-environmental behaviour is, easily accomplished substantial energy savings could be made. 

CO₂ emissions from non-domestic buildings - primarily workplaces - make up 18 percent of the UK's carbon footprint. A combination of technology advances and behavioural changes have the potential to make significant impact, but interventions have often been planned in ways which do not take into account the needs, levels of understanding and everyday behavioural contexts of building users - and hence do not achieve the hoped-for success.This paper provides a brief introduction to the Empower project, a current industrial-academic collaboration in the UK which is applying methods from user-centred design practice to understand diverse users' needs, priorities, mental models of energy and decision-making heuristics - as well as the affordances available to them - in a number of office buildings. We are developing and trialling a set of low-cost, simple software interventions tailored to multiple user groups with different degrees of agency over their energy use, which seek to influence more energy efficient behaviour at work in areas such as HVAC, lighting and equipment use. The project comprises an ethnographic research phase, a participatory design programme involving building users in the design of interventions, and iterative trials in a large office building in central London.

Recent international agreements on reducing energy consumption have led to a series of interventions in residential buildings, from modifying the building fabric to upgrading operating systems. To date, these attempts have met with limited success. One reason for this has been identified as the ‘rebound effect’, where the occupants’ respond to their home thermal environment change in unexpected ways after interventions. Often people decide to turn up the heating, to leave it on for longer, or to increase the average spatial temperature by heating more rooms. Although much of the research on heating patterns in dwellings has focused on identifying methods to predict and to assess thermal sensation, less is understood about the way occupants form their responses. Research presented in this paper focuses on mapping householders thermal discomfort responses. Empirical methods, drawn from the social and cognitive sciences, were used in a several studies, which monitored a small sample of UK households during winter of 2010. One of the tools used, the SenseCam, facilitates an automatic electronic diary collection by logging occupants’ responses in a systematic approach.SenseCam results enabled the mapping of participants’ activities in their home, in particular the estimation of clothing and activity level throughout the record period. The preliminary monitoring results show that different householders are interacting with their home thermal comfort systems in very different ways, and that their responses diverge from the current predictive models. Further analysisexamines the factors influencing responses to thermal discomfort and thereby energy consumption of individual in dwellings.