New research suggests that Government plans to achieve an 80% reduction in the CO2 emissions from existing UK homes by 2050 may be unrealistic because householders use energy efficiency initiatives to make their homes more comfortable rather than to save energy. Writing in a special issue of the Building Research & Information journal, researchers from the Carbon Reduction in Buildings (CaRB) Consortium present detailed new evidence on how people use energy in buildings. The researchers overturn beliefs surrounding technical improvements in the home by suggesting that energy efficiency measures seem to encourage householders to turn up the heat, leave the heating on for longer and heat more rooms. “The Government may have overestimated the impact its Great British Refurbishment programme will have on CO2 emissions,” said CaRB Consortium member Kevin Lomas, Professor of Building Simulation at Loughborough University. “Our research shows that some householders who install double glazing, insulation and energy-efficient boilers end up using fuel at close to the old levels because they are more concerned about comfort than saving energy. Even when energy prices rise, the reduction in demand for energy may be only temporary.”

The researchers believe that technical interventions alone will be insufficient to meet the Government’s targets. They propose a more integrated approach embracing economic, technical, social and behavioural factors. This would include targeting national refurbishment strategies at larger homes and other types of property where the greatest gains in energy reduction can occur, changes to the design and marketing of building products and services to improve energy performance, and a social marketing programme to establish ‘social norms’ for reducing temperatures in ‘overheated’ homes.

The framing of the problem of energy demand and CO2 emissions is crucial to its eventual success. The way in which technical interventions in buildings, such as higher insulation standards, improved boiler efficiencies or integrated renewable energy technologies, can directly affect carbon emissions is in principle relatively well understood. Yet it is an unavoidable fact that, despite many technical improvements to the UK building stock, CO2 levels continue to rise. There are many reasons for this. As well as consumers turning up the heat, some increases in emissions can be ascribed to economic growth, which leads to more or larger dwellings, which tend, over time, to contain more electrical items, and items that are also more energy intensive. There are a number of entangled and interacting economic, technical, social and behavioural factors at play.

To make progress at policy, strategy and implementation levels, it is vital to investigate effects such as these, to understand how people use energy in their home, their attitudes to energy use, the effects of energy costs and income levels, and the effectiveness of building regulations, etc.

The special issue of the Journal features seven papers and a commentary concerned with reducing the carbon emissions of existing buildings. All but one of these articles are by UK academics who were partners in the UK research consortium called 'Carbon Reduction in Buildings: A Socio-technical, Longitudinal Study of Carbon Use in Buildings' (CaRB),1 which sought:

* to improve the understanding of how people actually use energy in buildings
* to formalize this understanding in models that describe the current domestic and non-domestic building stock and the patterns of energy use
* to produce tools to assist policy-makers, consultants and others in their efforts to reduce national CO2 emissions

The project was undertaken during a period of rapidly intensifying interest and action by government and others in the area of climate change, carbon emissions and building energy use. For example, utility data at local authority level became available and there was the appearance of smaller, cheaper and more reliable monitoring equipment that enabled electrical energy demand to be recorded at short time intervals. These factors acted as a spur to particular avenues of enquiry, some of which were not envisaged at the project's initiation.

CaRB is distinguished from the other Carbon Vision Buildings consortia,2 and indeed from much previous work on energy in buildings, by its emphasis on the collection of field data of various types to understand the existing UK stock of domestic and non-domestic buildings; by longitudinal studies to understand how energy use has changed over time; and by bringing a transdisciplinary perspective to the problem. The research team took the view that the current technical models may be flawed by their poor treatment of the human dimension to the energy demand problem. Monitoring and both quantitative and qualitative household interviews were key to understanding this human dimension.

Professor Lomas’ article published in Volume 38 Issue 1 of Building Research & Information can be download for free from: http://tinyurl.com/BRI381Editorial.