This handbook is our first attempt to provide an overview of the many issues around managing carbon and greenhouse gases in the built environment, and we hope it will be useful as a primer for anyone new to the field and a reference guide for students and professionals alike. The hardest part of writing this book has been trying to strike the best balance between the scope and the depth of the coverage, and because of this some of the final contents have changed somewhat from our initial ideas. We hope these changes have been for the better in enabling a more specific coverage of the issues most relevant to the built environment, and we welcome any feedback for future editions.
The opening section of the book summarises the contexts in which those working to reduce emissions from the built environment operate – from global governance and climate change down to the more practical issues around reducing emissions from the built environment. The second section presents a more detailed coverage of these latter issues and how they may be addressed in specific built environmental contexts (new build, existing build and cities). By opening this section with energy generation we underline the ultimate dependence of all emissions reduction targets on decarbonising our energy supplies. The final section covers many of the protocols, standards, approaches, methods, tools and techniques that can, or must, be adhered to or employed as part of assessing energy consumption in the built environment and the emissions attributable to it. Identifying and selecting the most relevant of these have been a daunting task, and we apologise for any omissions and being mainly limited to English language sources.
Although we have included some illustrative case studies, it was never our intention to provide a template example for use in carbon and greenhouse gas accounting. In reality carbon and GHG assessments (or ‘footprints’) vary widely according to factors such as their subjects, aims, methods, tools, results and outputs, as well as any legislative requirements they are subject to – and any template would rapidly become out of date. Similarly, whilst there are many perfectly good commercial carbon accounting tools and services on the market we have not attempted to summarise or recommend any of these; not only will different projects require different tools, but also different users will judge those available on different criteria. However, we hope this handbook contains sufficient guidance and pointers to key publications to enable the development of carbon and GHG assessments for most common aspects of the built environment, whether users decide to use existing tools or develop their own.
Carbon and GHG management is a rapidly evolving, complex and contested field, and we are conscious that by even writing about some issues we are opening ourselves to accusations of bias. The issue of energy generation provides a case in point. The options for the scope of what to include in this chapter ranged from limiting it to building-integrated technologies up to a full coverage of all existing and possible future generation technologies. As with carbon and GHG accounting, the key problem was deciding where to set the boundaries. We have avoided discussing future technologies because of the uncertainties around them, and also because the urgent need to tackle climate change means that we should not let predictions of the potential of future technologies cloud our judgements over decisions that must be based on what works today. We could have also dodged the bullet of nuclear power by limiting our scope in a number of ways, but all of these would have required omitting other technologies which are also contributing to reducing emissions from the built environment.
A more building-specific issue that can provoke heated debate is providing heating, ventilation and air conditioning (HVAC). It is difficult to work in this field and not become an advocate of one or more approaches to meeting these demands. However, regardless of whether you favour passive or mechanical ventilation, or high thermal mass or light build, the priority should be identifying the most effective solutions in any given context. The same applies to identifying the most appropriate options for retrofitting buildings for energy efficiency: there is no one-sizefits-all approach, but some approaches are more generally applicable than others, and conversely some buildings are more individual than others. Identifying and implementing those solutions require pulling together the best available evidence, and we hope that this book will be a useful aid for doing so.
In 2004 the GHG Protocols Group set out five key principles of carbon accounting: relevance, consistency, completeness, transparency and accuracy. So how well do we think this text compares against them? With so much information that could be captured we’d never claim it was 100 per cent complete, and its accuracy will decline as the latest information changes over time, but we hope readers find it relevant and consistent, and we have done our utmost to ensure that it’s transparent. We hope you’ll find it useful, and we leave you with a little bit of satire for when the going gets tough and the figures simply refuse to add up.