Thermostat settings in English houses No evidence of change between 1984 and 2007

Rising demand temperatures are widely blamed for UK home energy use not declining over time despite the increased efficiency of dwelling envelopes and heating technologies The hypothesis that thermostat settings have risen over time is tested using a repeated cross-sectional social survey of owners of centrally heated English houses No statistical evidence for changes in reported thermostat settings between 1984 and 2007 is foundWhy then has home energy use not declined over time despite homes apparently becoming more efficient? There is evidence that the energy efficiency of homes has not improved as much as previously assumed Improvements in dwelling energy efficiency and increased penetration of central heating would have increased internal temperatures without occupants demanding higher temperatures Dwelling area heated or duration of heating or window opening during the heating season may have increased over time increasing temperatures or energy us

How household thermal routines shape UK home heating demand patterns

In homes in the UK, it is very common to operate space heating intermittently; the heating is usually switched off when the occupants are asleep at night and when they are out during the day. The strong association between heating operation and household routines leads to a morning peak in demand which, if it persists following electrification of heating, will require significant reinforcement of electricity supply networks. This paper examines factors that underpin how heating is used in the UK. A unique dataset of heating controller settings from 337 UK allows investigation of how patterns of heating operation in individual homes contribute to daily patterns of space heating energy consumption at the group level. A mixed method approach is followed, combining quantitative analysis of data with interviews with householders. The concept of thermal routines is introduced, bringing a time dimension to the consideration of domestic thermal comfort and recognising that demand for space heating is linked to patterns of practices in the home, which are themselves linked to social routines, e.g. timing of work and school. The results from this study suggest that household thermal routines around 07:00 in the morning are a particularly important consideration for a transition to future energy systems with a high proportion of low carbon heat. Factors that currently limit flexibility of heating demand in the UK are identified, and the implications for a transition to low carbon heating sources are discussed

A panel model for predicting the diversity of internal temperatures from English dwellings

Using panel methods, a model for predicting daily mean internal temperature demand across a heterogeneous domestic building stock is developed. The model offers an important link that connects building stock models to human behaviour. It represents the first time a panel model has been used to estimate the dynamics of internal temperature demand from the natural daily fluctuations of external temperature combined with important behavioural, socio-demographic and building efficiency variables. The model is able to predict internal temperatures across a heterogeneous building stock to within ~0.71°C at 95% confidence and explain 45% of the variance of internal temperature between dwellings. The model confirms hypothesis from sociology and psychology that habitual behaviours are important drivers of home energy consumption. In addition, the model offers the possibility to quantify take-back (direct rebound effect) owing to increased internal temperatures from the installation of energy efficiency measures. The presence of thermostats or thermostatic radiator valves (TRV) are shown to reduce average internal temperatures, however, the use of an automatic timer is statistically insignificant. The number of occupants, household income and occupant age are all important factors that explain a proportion of internal temperature demand. Households with children or retired occupants are shown to have higher average internal temperatures than households who do not. As expected, building typology, building age, roof insulation thickness, wall U-value and the proportion of double glazing all have positive and statistically significant effects on daily mean internal temperature. In summary, the model can be used as a tool to predict internal temperatures or for making statistical inferences. However, its primary contribution offers the ability to calibrate existing building stock models to account for behaviour and socio-demographic effects making it possible to back-out more accurate predictions of domestic energy demand

Household thermal routines and their impact on space heating demand patterns

Patterns of home heating demand during the day have significant implications for the design of energy networks and will be an important consideration in the introduction of low carbon heating systems such as heat pumps. In homes in the UK it is very common to operate space heating intermittently; the heating is usually switched off when the occupants are asleep at night and when they are out during the day. The strong association between heating operation and household routines leads to a morning peak in demand which, if it persists following electrification of heating, will require significant reinforcement of electricity supply networks. This paper examines factors that underlie current UK home heating practices. A unique dataset of heating controller settings from 337 UK homes with smart heating controllers allows investigation of how patterns of heating operation in individual homes contribute to daily patterns of space heating energy consumption at the group level. A mixed method approach is followed, combining quantitative analysis of data with interviews with householders, drawing on insights from social practice theory. The peak level of space heating demand is found to be higher in the morning than the evening. The concept of thermal routines is introduced, bringing a time dimension to the consideration of domestic thermal comfort and recognising that demand for space heating is linked to patterns of practices in the home, which are themselves linked to social routines, e.g. timing of work and school. The results from this study suggest that household thermal routines around 07:00 in the morning are a particularly important consideration for a transition to future energy systems with a high proportion of low carbon heat. Factors that currently limit flexibility of heating demand in the UK are identified and the implications for a transition to low carbon heating sources are discussed

All about size? – The potential of downsizing in reducing energy demand

Residential energy consumption is one of the main contributors to CO2 emissions in the UK. One strategy aimed at reducing emissions is to increase retrofitting rates of buildings. In this paper, an alternative approach is discussed and its potential impact on energy use assessed, that of downsizing (moving to smaller homes). Reviews of previous research show that a wide range of what can be termed psychological barriers exist to downsizing, such as the loss of ownership and independence, concern about what to do with possessions, not having enough space for visitors, and attachment to one’s home. Benefits of downsizing from a personal perspective are economic, with lower bills and/or rent, release of capital, lower maintenance costs, and also potential lifestyle improvements including living in easier-to-maintain and more age-appropriate housing. Wider societal benefits include the potential to significantly reduce energy consumption, and mitigating the housing crisis in cities where not enough properties are available. Empirical analysis on a nationally representative sample in England showed that building size alone accounts for 24% of the variability in energy consumption (compared to 11% of household size). If single-person households with more than two bedrooms downsized by one bedroom, energy-savings of 8% could be achieved, and if single-person households occupied only one bedroom, savings of 27%. Data also showed a significant amount of underoccupation, with almost two-thirds of households having more bedrooms than considered necessary compared to the bedroom-standard. However, analysis also revealed a structural barrier to downsizing, namely the lack of available alternative, smaller houses. The evidence would suggest that downsizing could realize significant energy savings, and address a range of other social benefits. However, against this stand significant personal interests, inadequate alternative housing and other infrastructure issues. Promoting downsizing as a means to achieve energy policy goals is therefore a potentially significant but socially challenging policy option

Size and the City: The potential of downsizing in reducing energy demand and increasing quality of life

Recent decades have seen a tremendous growth in the population, particularly in cities. London, for example, has increased from about 6.8 million to 8.2 million over 20 years from 1991 to 2011. Additionally, we have seen substantial demographic change, with an increasing life expectancy and other factors resulting in a larger number of households with only one or two people. One consequence of this is that older people can end up living in inappropriate housing being too large for their needs, with high heating bills and stairs restricting mobility. In addition, this also contributes to the decreasing availability of housing for the growing population. Ultimately, this can lead to unnecessary use of energy and carbon emissions. One potential approach would be to promote downsizing amongst those who live in larger-than-needed properties (defined in relationship to a standard). Some people might choose to live in large properties – for those the question might be for whom could downsizing be rendered an attractive option. For those keen on downsizing, the question is more how it can be realized, i.e. what barriers need to be removed and what help given. In any case, for those who downsize, this could result in significant release of equity (for home owners) or reduced rent, in addition to lower bills and potentially more suitable accommodation in terms of access and mobility. Potential benefits for the wider population would be greater availability of housing stock. This paper will address this issue in different ways. Firstly, empirical data will be presented on the effect of housing size on energy consumption. A sample of N = 991 households, approximately representative for the English population, is analysed with regard to the impact of housing size and housing type on energy consumption. Results show that those two predictors are of greatest importance, and together explain about 29% of the variability in the log-transformed annual energy consumption, surpassing all other variables. In addition, the analysis calculates the amount of under- and overpopulation of housing to give an estimate of the distribution of living space. Secondly, the paper will discuss the benefits of downsizing for the population. A detailed literature review is performed. The results address the benefits of downsizing and highlight which factors would promote downsizing. One issue that has been shown previously, was that those who could downsize felt that little adequate alternative housing was available. Also, general potential effects are discussed, such as freed up living space, and issues of intergenerational justice. Thirdly, the paper will look beyond downsizing at other options such as co-housing, creating multiple-generation homes, or taking a lodger. The prevalence of these schemes will be discussed, and their potential highlighted

Behaviour, practice – whatever? A theory-agnostic framework for describing and informing demand-side response

Different theoretical perspectives present diverse interpretations for why and how people may (or may not) be able to vary their electricity consumption patterns, and often propose different approaches to facilitating demand-side response (DSR). The framework set out here is suggested as a way of matching and marrying these various approaches with the goal of exploring how to achieve the maximum possible demand response which people are happy and able to provide. The framework is based around ‘electricity-relevant dimensions’, or factors which may be considered to be associated in some way with a person or people’s electricity use – activities engaged in, location, room temperature, and so on. Within each dimension, any at instant in time, certain states (such as ‘walking’ or ‘watching TV’ for activity) are more or less possible/acceptable than others for a variety of reasons. Effective DSR is understood as involving influencing adoption of those states with lower (or higher, as necessary) electricity outcomes at certain times, from a ‘phase space’ of possible options. This paper describes how the framework can be used to consider the role of DSR interventions with their roots in different theoretical positions, such as changes in material conditions or competencies (associated with social practice theory), or in the framing of messages to activate loss-aversion (behavioural economics). It is intended to prompt consideration of how such approaches (and their proponents) could work together to optimize the potential of DSR programmes and policies, and is illustrated throughout with real and hypothetical examples

Generating empirical probabilities of metabolic rate and clothing insulation values in field studies using wearable sensors

This research introduces a mixed-method framework to estimate metabolic rate and clothing insulation as objective and quantitative variables. Methods included automated visual diaries and both environmental and wearable sensors. Applying this framework in an exploratory study, during the winters of 2012 and 2013, allowed empirical probabilities of metabolic rate and clothing insulation values to be generated. The results indicate that current standards overestimate winter clothing insulation by 22% but underestimate residential metabolic activity by 9%. Beyond reviewing the standards thresholds, these probability distributions may be used as input to building energy simulation (BES) programs

Knowing me, knowing you: the role of trust, locus of control and privacy concern in acceptance of domestic electricity demand-side response

Choosing to take part in a demand-side response (DSR) programme entails accepting external influence over one’s energy consumption patterns, such as through price or direct load control (DLC) signals. If participation is low, the programme will be ineffective. How might people’s perceptions of their relationship with the influencing entity affect the likelihood of participation? This study used a representative survey of Great Britain (N=2002) to explore the importance of trust, privacy concern and locus of control for acceptance of different approaches to influencing electricity consumption. Survey respondents were randomly shown a description of one of five DSR products (static time of use [TOU] tariff, static TOU with automated response to price changes, dynamic TOU, dynamic TOU with automated response, and DLC), framed as being offered by their electricity supplier. They then responded to a number of scales including those intended to measure trust in their supplier, privacy concern and locus of control. Controlling for demographic variables, trust in electricity supplier was significantly positively associated with acceptance of all tariffs, although the effect size was smaller for the automated TOU tariffs. The specific measure of trust in the supplier to ensure a reliable electricity supply was significantly negatively associated with acceptance of the dynamic TOU tariff. Privacy concern was significantly negatively associated with acceptance of all tariffs, with the strongest effect for the automated dynamic TOU tariff. Locus of control was a significant factor only in the case of DLC, where external locus was related to higher acceptance. These results suggest the existing low levels of trust in energy companies in the UK may present a challenge in securing uptake of DSR, and an opportunity to trusted entrants from other sectors. Automation within the home may mitigate trust concerns, but people must have confidence in the privacy of this arrangement. DLC may be viewed especially positively by people who currently perceive themselves to have little control over their energy use, but protections should be in place to ensure they are not exploited