Building Futures

Managing energy in the built environment

Jane Powell, Jennifer Monahan, Chris Foulds

• Publisher: Taylor & Francis
• Year: 2015
• eBook ISBN: 9781317379812
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

A reduction in the energy demand of buildings can make a major contribution to achieving national and international carbon reduction goals, in addition to addressing the interlinked issues of sustainable development, fuel poverty and fuel security. Despite improvements in thermal efficiency, the energy demand of buildings stubbornly remains unchanged, or is only declining slowly, due to the challenges posed by growing populations, the expectations of larger, more comfortable and better equipped living spaces, and an expanding commercial sector.

Building Futures offers an interdisciplinary approach to explore this lack of progress, combining technical and social insights into the challenges of designing, constructing and operating new low energy buildings, as well as improving the existing, inefficient, building stock. The twin roles of energy efficiency, which is predominantly concerned with technological solutions, and energy conservation which involves changing peoples' behaviour, are both explored. The book includes a broad geographical range and scale of case studies from the UK, Europe and further afield, including Passivhaus in Germany and the UK, Dongtan Eco City in China and retrofit houses in Denmark.

This book is a valuable resource for students and academics of environmental science and energy-based subjects as well as construction and building management professionals.

1
Energy in the built environment

1.1 Introduction

Energy is essential for all societies in order to meet their needs for food, shelter, industry and commerce. Energy-dense fossil fuels have allowed most countries to develop in a way that would have amazed pre-industrial society. Escalating populations, with rising standards of living, drive an ever-increasing global demand for energy, resulting in the interlinked problems of climate change, pollution, limits to resources, fuel poverty and energy security. As energy resources become scarcer, their extraction will be more expensive and cause increased environmental damage, leading to higher prices and increased fuel poverty.

However, despite this need to curb our demand for energy, in the words of the International Energy Agency, ‘taking all new developments and policies into account, the world is still failing to put the global energy system onto a more sustainable path’ (IEA, 2012, p. 1). Not only are we failing to progress sufficiently towards our long-term carbon targets, but we are also failing to tackle the inequity in access to energy resources, the health issues associated with energy use and the limits to our energy resources.

Globally we mainly use energy for the residential sector (25 per cent), services (9 per cent), industry (31 per cent) and transport (31 per cent) (2012 figures) (Figure 1.1). In addition to the residential sector, the energy used by ‘services’, which includes commercial, retail, public services, leisure sector, hospitals and education sectors, is also almost entirely associated with buildings. World-wide, buildings are considered to have an energy demand of over one-third of global energy and half of global electricity demand (IEA, 2013). So, if we are to tackle our energy-related problems successfully, the built environment needs to be a major contributor to reducing energy demand and carbon emissions. Technically, this reduction is relatively straightforward for buildings, compared to the logistical problems posed by other sectors such as transport. However, improvements in the energy efficiency of buildings are undermined by various factors, such as population growth and increases in living standards. Indeed, the number of households world-wide is predicted to grow by 67 per cent and the floor area of the service sector by almost 195 per cent by 2050 (from 2007) (OECD/IEA, 2011).

Figure 1.1 Global energy demand by sector (%) (2012).

Source: IEA (2014).

Significant progress has been made to improve the thermal envelope of buildings, but the actual energy demand has not declined as much as predicted. In addition to technical failings, this problem is also due to how our buildings are used, suggesting that a more holistic, interdisciplinary approach is needed to explore the technical, environmental and social challenges of designing and using low-energy buildings. We are unlikely to meet our energy and carbon targets unless an interdisciplinary approach is used to tackle this challenge. The need for such an approach has been echoed by the UK Royal Academy of Engineers (2010), which identified an urgent need for multidisciplinary research in building design, engineering, energy and carbon efficiency that would inform the construction industry of the potential of alternative initiatives.

This first chapter initially explores why energy demand is a problem, discussing climate change, fuel poverty and energy security. We then examine how much energy we use globally, in the EU and the UK, and then focus on different energy sectors (industry, commercial, residential and transport), identifying why buildings are particularly important. This will include why the amount and types of energy we use are important, and in particular the carbon consequences of the fuel used, especially the electricity fuel mix. Trends in energy demand will be examined, identifying the underlying demographic and sociotechnical drivers for changes in energy use in buildings. We then go on to discuss the challenges to reducing energy demand in buildings and explore examples of policy solutions that are being used to address these challenges.

1.2 Why is energy use a problem?

Energy, of course, is used by everyone, in all parts of the global economy, although its form varies considerably. The poorest people use ‘local fuels’ such as wood and manure to cook basic ingredients and to keep warm, while Western societies use energy, predominantly from fossil fuels, to extract resources and manufacture products, for transportation and to provide services (heat, cooling and hot water) at work and in our homes. But this increasing demand for energy is leading to many important global challenges, in particular climate change, fuel poverty and energy security.

1.2.1 Climate change

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia… . It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

(IPCC, 2013, p. 2)

Human activity, resulting in the emission of carbon dioxide (CO₂) from the combustion of fossil fuels, is augmenting the atmospheric concentration of greenhouse gases (GHGs) at an unprecedented rate. The accumulation of atmospheric concentrations of all GHGs has increased since the inception of the Industrial Revolution in 1750 (IPCC, 2013), with global CO₂ emissions from fossil fuel combustion and cement production increasing on average by 2.5 per cent per year over the past decade (Friedlingstein, 2014). The impacts on human society will be widespread and will involve destructive weather events, the disruption of food production and impacts on human health (IPCC, 2014a). While there is still debate over the potential future impacts of climate warming, a 2 ºC rise has become the accepted threshold beyond which climate change effects will be ‘dangerous’ (Copenhagen Accord, 2009).

However, there is a ‘significant gap’ between the current trajectory of global GHG emissions and the ‘likely chance of holding the increase in global average temperature below 2 ºC or 1.5 ºC above pre-industrial levels’ (UNFCCC, 2011, quoted in Peters et al., 2012, p. 1). To keep temperature increases below 2 ºC is likely to require challenging global CO₂ mitigation rates of over 5 per cent per year, partly because of the likelihood of increased emissions in some regions, in addition to meeting the long-term carbon quota (Raupach et al., 2014). Moreover, if there is a delay in starting mitigation activities, the target of remaining below 2 ºC becomes even more difficult, if not unfeasible. Many of these higher rates of mitigation rely on negative emissions, using emerging technologies such as carbon capture and storage possibly linked to bioenergy, which have high risks due to potential delays or failure in their development and large-scale deployment (Peters et al., 2012). As a consequence of the challenges of achieving these mitigation rates, the likelihood of keeping climate change within 2 ºC is being increasingly called into question, with a trajectory of 4, 5 or even 6 ºC seeming more likely (Jordan et al., 2013).

Nevertheless, society’s principal response to the challenge of climate warming needs to be one of mitigation, with urgent and radical moves towards decarbonisation (Anderson et al., 2008). The global political response towards achieving long-term reductions in emissions began with the United Nations Framework Convention on Climate Change in 1994 and the first legally binding protocol, the Kyoto Protocol, adopted in 1997 and entered into force in 2005. Under the Kyoto Protocol, governments committed to reduce their country’s emissions by a target date. The UK, for example, committed to reduce its emissions by 12.5 per cent from 1990 levels by 2012; this it easily achieved, mainly as a result of the economic recession and exporting its carbon footprint (i.e. many products used in the UK are manufactured in other countries, so the associated carbon emissions are not attributed to the UK).

Globally, carbon emissions nearly doubled from 1973 (15,633 mtCO₂) to 2012 (31,734 mtCO₂) (OECD/IEA, 2014). Carbon dioxide emissions from global fossil fuel combustion and cement production have increased every decade over the last 50 years, starting from an average 3.1 ± 0.2 GtC/yr in the 1960s, to 8.6 ± 0.4 GtC/yr during 2003–2012 (Le Quéré et al., 2014). (Note that these values are expressed as carbon rather than carbon dioxide.) It might have been expected that the global financial crisis in 2008–2009, with its impact on economic activities, would have slowed the rate of growth in emissions. Its effects were short-lived, however, owing to a substantial growth in the emerging economies, a return to emissions growth in developed economies and an increase in the fossil-fuel intensity of the world economy (Peters et al., 2012). In terms of CO₂ emissions per person, the CO₂ emissions in 2012 were 1.4 tC per capita/yr globally, and 4.4 (USA), 1.9 (China), 1.9 (EU) and 0.5 (India) tC per capita/yr (Le Quéré et al., 2014).

Carbon dioxide emissions from fossil fuel combustion and industrial processes contributed to approximately 78 per cent of the total GHG emissions during the period 2000–2010, while the use of buildings contributed 19 per cent of GHG emissions (2010) (IPCC, 2014b). Note that the emissions associated with the construction of buildings is included in the industrial sector. Even though many countries are seeking ways to meet carbon emission targets by reducing their energy demand, the energy demand from buildings is projected to double and CO₂ emissions to increase by 50 to 150 per cent by 2050 in baseline scenarios. However, there are considerable opportunities to reduce this demand using energy-efficient technologies, policies and know-how. In developed countries it is also considered that up to 50 per cent of energy demand could be reduced through behavioural and lifestyle changes by 2050 (IPCC, 2014b).

1.2.2 Fuel poverty

Fuel poverty is a term used in the UK and some other EU countries to describe the lack of access to energy. In the United States ‘energy insecurity’ is used, and in 20 OECD countries ‘lacking affordable warmth’ (Liddell and Morris, 2010). There is also conflicting use of the terms ‘energy’ and ‘fuel poverty’ within the EU (Thomson and Snell, 2013a), with ‘energy poverty’ being the more common term in developing countries. All these terms, however, focus on a lack of access to adequate, ‘clean’ (i.e. with low particulate emissions) energy, whether this is due to (1) energy resources not being available, (2) the lack of...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of illustrations
• Foreword
• Preface
• Acknowledgements
• Acronyms and units
• 1 Energy in the built environment
• 2 Reducing energy demand
• 3 Lifecycle energy of buildings
• 4 Energy performance gap
• 5 Retrofitting buildings
• 6 The Passivhaus energy-efficiency standard
• 7 Ventilating buildings
• 8 Building futures
• Glossary
• Useful resources
• Index