Search

China is the largest driver of growth in the global building sector. The longstanding construction boom across China has generated a massive flow of materials with significant associated embodied energy consumption and carbon emissions. Despite the serious implications for global emissions, there exist a very limited number of macro-level studies on embodied energy of Chinese buildings, with even fewer exploring future scenarios. There is therefore little in the way of an evidence base to offer policy makers. We develop a probabilistic model to forecast the possible trajectories of embodied energy of residential buildings over the medium to long term in the Chinese urban context. Our results provide clear evidence to substantiate the importance of embodied energy of new construction, which we find to be over 0.3 times the operational energy of existing stock between 2010 and 2018. If current trajectories are followed, embodied energy is likely to peak around 2027, with a 95% credible interval ranging from 87 to 283 Mtce (61 to 198 Mtoe) and a mean of 170 Mtce (119 Mtoe). We show that building lifetime has a substantial impact on future annual and cumulative embodied energy. Our findings reinforce the need to take a whole-life perspective to formulate policies addressing building energy as part of China's efforts to meet the announced overarching target of achieving carbon neutrality by 2060.

Environmental product declarations (EPD) to EN 15804 provide information about the embodied carbon dioxide of construction products – their life cycle greenhouse gas emissions – alongside reporting the use of renewable and non-renewable primary energy and secondary fuels, among the other environmental indicators. As the number of EPD to EN 15804 increases, they become a useful data resource to consider these impacts. In moving towards a reduction in the embodied carbon of products, it is necessary to use renewable energy resources efficiently to allow the transition to net zero; this is because of the increasing demands on renewable energy to decarbonise industry, transport and domestic energy consumption and the limited capacity to expand renewable generation. This paper reviews published EPD data for structural and reinforcing steels, cement, bricks and structural timber products, and considers, for the cradle to gate ‘product’ life cycle stage, exploring the relationship of embodied carbon with embodied energy (total energy used), the balance of renewable and non-renewable energy, and the efficient use of energy. It is found, for bricks and timber, that EPD show products that use a greater percentage of renewable energy have higher embodied energy, suggesting a less efficient use of renewable energy for these products.

This paper examines how global trade shapes and intensifies disasters. Juxtaposing three basic, everyday consumer goods – a t‐shirt, a brick, and a tea bag – with disasters manifesting in their respective global supply chains, it highlights how climate change, local environmental degradation, and carbon emissions are dynamically shaped by consumption. Analysis of data collected in South and Southeast Asia reveals that local environmental degradation linked to international trade interacts with global climate change and the policies intended to mitigate it, influencing how and where disasters manifest. Underpinning this analysis is the physical and conceptual presence of the container. With more and more of the natural environment packaged and redistributed for global trade, the container thinking that underpins these logistics is increasingly imbricated in environmental processes. Indeed, as this paper aims to show, the container logic that frames analysis of these processes – linked to and drawn from the logistics of global trade – serves as both obfuscator and actor in the global landscape of environmental risk.

Reducing energy and associated carbon emissions from the existing built environment is critically important to meet our climate goals. Heritage buildings are often presented in the literature as energy inefficient, and uncomfortable to inhabit. There is however little research into residents’ perceptions of comfort in these buildings to support this view, while there is some evidence to suggest that heritage buildings may be more thermally comfortable than generally assumed. This paper interrogates a survey of 147 residents of pre-1940 heritage buildings in Cumbria, UK, to examine residents’ comfort perceptions. This survey is compared with secondary data from other UK studies on residential comfort. Results are elucidated with more detailed responses from interviews with 16 heritage households. Three key findings were made. First, heritage buildings are perceived to have broadly comparable thermal performance to more modern UK buildings by their residents. Second, the survey results and interviews found that residents perceive their buildings to perform particularly well in summer, keeping comfortably cool in hot weather. In contrast, the literature suggests that newer homes often appear to suffer from overheating. Third, although many Cumbrian residents found their buildings draughty, a large percentage would not prefer less ventilation, with case study participants citing their enjoyment of fresh air. These results are highly relevant for successful approaches to renovation and the implementation of the European Renovation Wave. Renovations are often promoted to heritage residents for their comfort improvement potential. However, if buildings are already perceived as broadly comfortable this may not be a key driver. Alternative motivations may therefore need to be identified to drive renovation uptake. The findings also highlight the importance of maintaining positive aspects such as good summer performance.

Two key benefits of building retention and adaptation, over demolition and new build are identified in the academic literature: these are, the conservation of heritage, and reductions in embodied greenhouse gas emissions from construction materials. However, there is limited evidence on how these benefits are considered in decisions to demolish or adapt buildings in practice. A four year research project, including expert interviews, focus groups and three detailed case studies from the UK, Netherlands, and Australia, developed extensive data on how decisions were arrived at to demolish or retain individual buildings within larger urban development sites. The research found that heritage and embodied impacts are considered quite differently. Heritage is frequently a key driver towards retaining individual buildings. However, considerations of embodied emissions are seldom considered in the decision. Where there are insufficient arguments based on heritage value, many buildings are therefore demolished and replaced rather than retained. However, research has shown that in many cases, if embodied impacts are considered as well as operational impacts, this will lead to far higher whole life greenhouse gas emissions. To reduce the impact of construction on the environment it is therefore crucial that we calculate the embodied as well as operational impacts of demolition decisions and retain and refurbish buildings where this is the lower carbon choice. This paper proposes that understanding why ‘heritage’ is now accepted as a reason for retaining buildings might offer some lessons about the way forward for embodied carbon. Using heritage arguments as a basis, the paper then proposes that the introduction of a policy driver for retention and against demolition, and the conversion of environmental value into economic uplift, are likely to be necessary conditions to encourage the retention of buildings for lower whole life carbon.

Infrastructure is critical for the economic and social prosperity of society. Some large infrastructure projects are also critical for the future of society due to their intergenerational nature and long lifespan. Understanding the social value of infrastructure is therefore important to deliver a socially successful as well as technically successful project. Stakeholder engagement, in turn, is critical in understanding and identifying social value; however, the strength of this relationship is often underestimated during project development. The impact of this underestimation can be detrimental to a project. Using the case study of the Didsbury Flood Storage Basin Improvements Scheme in Greater Manchester, UK, this paper demonstrates how the stakeholder engagement process is intrinsically linked to social value preservation, creation and enhancement on infrastructure projects. It is argued that by investing time, resources and money in the stakeholder engagement process, the social value creation and enhancement on a project can be significant. If this investment is missing on a project, the social value perceived to be received by stakeholders diminishes. Therefore, this paper calls for a greater understanding of the interdependency between the stakeholder engagement process and social value, and a need for an appreciation of this relationship within the infrastructure sector.

With one of the highest carbon footprints, the construction sector should be at the forefront of climate action. Reducing embodied impacts of construction also means ensuring that buildings are durable, low maintenance, and fit for purpose, while maximizing resource efficiency. However, thirty years in to research in this field, embodied impacts continue to be ignored in the majority of building projects. This paper traces the recent history of embodied impact assessment within industry best practice in two contrasting countries, the UK and Sweden. Our data is drawn both from personal involvement in a number of projects and from qualitative case studies of the development of low embodied impact buildings. Through these we consider what has historically held progress back, what the new drivers are in both countries, and what the remaining barriers (both overt and hidden) might be. By applying social power theories we identify deep and complex reasons for the lack of traction, including in policy formation and professional practices. The insights provided help to explain the slow progress so far, as well as to support increased reduction of emissions across the building sector, and thus enable progress towards achieving several key Sustainable Development Goals.

In the Mediterranean region façade shading systems are used to reduce operational energy, 9 particularly cooling loads. However, operational savings do not necessarily translate into net energy 10 savings unless they outweigh the embodied energy/carbon required to manufacture, install, 11 maintain, and dispose of these systems. This study analyses two shading devices, louvers and 12 meshes, from a whole-life perspective in Malta. We first establish, through dynamic energy 13 modelling, the operational energy and carbon savings achieved, and results show that both louvers 14 and meshes are capable of savings in terms of operational energy—20% to 40% compared to the 15 base case. Secondly, we establish the embodied energy and carbon through a life cycle analysis. 16 Although based on the limited data available for Malta, findings suggest that net energy and carbon 17 savings are only achieved by two of the 22 configurations investigated, both mesh systems. These 18 results highlight the urgent need to investigate shading systems to establish net energy and carbon 19 whole-life balances. The risk is otherwise that we will save less operational energy in the future, 20 from decarbonised energy grids, than we have already spent through a surge of embodied energy 21 from current, carbon intensive grids, therefore exacerbating the climate crisis.

Knowing the size of building stock is perhaps the most basic determinant in assessing energy use in buildings. However, official statistics on urban residential stock for many countries are piecemeal at best. Previous studies estimating stock size and energy use make various debateable methodological assumptions and only produce deterministic results. This paper presents a Bayesian approach to characterise stock turnover dynamics and estimate stock size uncertainties, applied here to China. Firstly, a probabilistic dynamic building stock turnover model is developed to describe the building aging and demolition process, governed by a hazard function specified by a parametric survival model. Secondly, using five candidate parametric survival models, the building stock turnover model is simulated through Markov Chain Monte Carlo to obtain posterior distributions of model-specific parameters, estimate marginal likelihood, and make predictions of stock size. Thirdly, Bayesian Model Averaging is applied to create a model ensemble that combines model-specific posterior predictive distributions of the recent historical stock evolution pathway in proportion to posterior model probabilities. Finally, the Bayesian Model Averaging model ensemble is extended to forecast future trajectories of residential stock development through 2100. The modelling results suggest that the total stock in China will peak around 2065, at between 42.4 and 50.1 billion m2. This Bayesian modelling framework produces probability distributions of annual total stock, age-specific substocks, annual new buildings and annual demolition rates. This can support future analysis of policy trade-offs across embodied-versus-operational energy consumption, in the context of sector-wide decarbonisation.

Life Cycle Assessment (LCA) is increasingly used as an early-stage design-decision tool to support choices of structural system. However LCA modellers must first make numerous methodological decisions, and the resultant wide variations in approach are often inadequately described by the modellers.\ud \ud This paper identifies, and quantifies, the three major areas of methodological variation. These are: temporal differences in the stages considered; spatial differences in the material boundaries; and physical disparities in the data coefficients. The effects are then demonstrated through a case study of a student residential building in Cambridge. The cross-laminated timber (CLT) structure is compared with concrete frame, steel frame and load-bearing masonry, considering the influence that varying the temporal boundaries, the data coefficients, and the spatial boundaries has on the choice.\ud \ud While for this building CLT is confirmed as the lowest impact material, the paper demonstrates that varying the methodological choices can change the results by an alarming factor of 10 or even more. The findings confirm the need for the utmost clarity and transparency with all LCA calculations. Making wider industry or policy decisions based on LCA results should be undertaken with extreme caution.

In order to meet the mid-century carbon reduction targets and to mitigate climate change and global warming it is imperative that embodied carbon in the built environment receives immediate attention from policy, industry and academia. To shed light on how to accelerate a wider uptake of embodied carbon assessments in buildings, an industry academia collaboration was funded by Innovate UK and the Engineering and Physical Sciences Research Council (EPSRC). Implementing Whole Life Carbon in Buildings (IWLCiB) has been the resulting project, a cooperative endeavour led by key academics and practitioners in the UK. Over the course of the project, three independent environmental consultants have produced a total of fifteen embodied carbon assessments across various building types, all starting from the same information including building specification and bill of quantities. These assessments have then been reviewed and analysed in detail by the academic team to establish similarities, differences, and common challenges and pitfalls.\ud \ud This paper reports on the project’s numerical findings by life cycle stages and building type. Detailed results are presented for each of the five case studies, showing elements of agreement and, most often, of variation. Additionally, each of the life cycle stages as defined by the TC350 standards is analysed both numerically and in terms of its contribution towards the whole life embodied carbon. The results show that significant discrepancies consistently exist even when the initial information available to the assessors is the same. The many assumptions that are necessary throughout the assessments inevitably present a barrier to consistency and convergence of the outputs. The numerical analysis also reveals that all life cycle stages account for important shares of the whole life carbon, and that therefore partial assessments – e.g. cradle-to-gate - are not sufficient if carbon reductions are to be realistically achieved. Yet, life cycle assessment remains the best tool for environmentally informed decision making. Future research in the field should continue to address the challenges identified in this article and work towards greater understanding and reliability of the numbers produced.

Life cycle assessment (LCA) is becoming increasingly mainstream as an early-stage design-decision tool for buildings. Still, there are considerable variations in how the method is currently used, leading to limitations in comparing the results and the conclusions that can be drawn. These variations are due to several factors and LCA modellers must make multiple methodological decisions during an assessment. This has resulted, unsurprisingly, in a variety of approaches, and a wide range of outcomes. Academics have produced numerous case studies on particular buildings, aiming towards a detailed understanding of the energy and carbon impacts. However, very few case studies are detailed enough to allow for an in-depth comparison. This article investigates in detail these embodied carbon assessments, considering the data used and the methodological assumptions made. An in-depth analysis shows that there are still considerable variations in how the methodology is applied, leading to substantial limitations in comparing results and drawing conclusions. Results may differ by two orders of magnitude, thus limiting the understanding of how real mitigation might best be achieved. Without immediate action, embodied carbon will become a ‘second wave’ of performance gap in environmental assessments of buildings. Both greater transparency and greater conformity must be embraced by the LCA community and enforced by policymakers and professional bodies.

This paper publishes the results from a major five year International Energy Agency research project which investigated the reduction of embodied energy and greenhouse gas emissions over the whole life (‘cradle to grave’) of buildings. Annex 57 collated and analysed over 80 detailed quantitative and qualitative building case studies from the participating nations. \ud \ud For many years the multiple variations in methodological approach of case studies to assess the whole life embodied impacts of buildings have presented a major challenge for politicians and other decision makers. Any real change in design and construction practice has also proved elusive. This paper describes a modified research synthesis and meta analysis as a novel and valid method for drawing meaningful conclusions from large sets of significantly diverse studies. \ud \ud The quantitative analyses consider embodied impacts of the product stage, replacement, and end of life stages, of new and refurbished buildings, and of different building assemblies and construction materials. The product stage is shown to dominate in most cases, with the median value around two thirds of the whole life embodied impacts, with replacements the next highest with a median figure of around 25%; however replacements in five studies were over 50% of the whole life impacts. It should be noted that several life cycle stages are still missing from these studies.\ud \ud The case studies included eleven refurbishment projects, in which energy efficient measures and low carbon technologies were retrofitted to existing buildings; for these projects the median product stage impact was found to be just under half that for the new build projects. While further research is required to compare the operational energy use in the new and refurbished buildings, this suggests that such energy refurbishments have a significantly lower impact than new buildings. Several other studies considered the impacts from technical equipment and internal fixtures and fittings, both frequently excluded, and demonstrated that they can be responsible for up to 45% of the whole life embodied greenhouse gases and up to 48% of the whole life embodied energy. \ud \ud Finally, the paper combines the analysis of the quantitative case studies with that of qualitative studies, to explore the impact of contextual factors at both policy and project level in significantly reducing the embodied environmental impacts of buildings. The case studies have shown that planning authorities, major clients, developers, and individual designers, can all play an important role in reducing embodied impacts through encouraging innovation.\ud \ud The paper concludes with recommendations for policy makers, designers and LCA modelers which will support and effect real reductions in the whole life embodied impacts of buildings.

With more intense rainfall and sea level rises predicted, an increasing number of people across the UK are vulnerable to flood events. The government has pledged more funding for flood infrastructure planning, design and management. However, schemes tend to focus on technical solutions, with the social impact, including needs and concerns of the local community, seen as secondary. Based on a detailed examination of three case studies in England, this paper identifies the mechanisms through which current processes restrict industry professionals from considering and incorporating the social perspective, often despite seemingly effective community engagement. The paper argues for an approach that incorporates social concerns alongside technical ones. Rather than ‘community engagement’, it is argued that ‘co-production’, in which lay communities work alongside technical experts in the design of flood risk alleviation schemes, would enable a final outcome that is both more socially acceptable and more technically successful.

Building lifetime and stock turnover are both key determinants in modelling building energy and carbon. However in China, aside from anecdotal claims that urban residential buildings are generally short-lived, there are no recent official statistics, and empirical data are extremely limited. We present a system dynamics model where survival analysis is used to characterise the dynamic interplay between new construction, aging, and demolition of residential buildings in urban China. The uncertainties associated with building lifetime were represented using a Weibull distribution, whose shape and scale parameters were calibrated based on official statistics on floor area up to 2006. The calibrated Weibull lifetime distribution allowed us to estimate the dynamic stock turnover of Chinese urban residential buildings for 2007 to 2017. We find that the average lifetime of urban residential buildings was around 34 years, and the overall residential stock size reached 23.7 billion m2 in 2017. The resultant age-specific sub-stocks provide a baseline for the overall stock, which&mdash, along with the calibrated Weibull lifetime distribution&mdash, can be used in further modelling and for analysis of policies to reduce the whole-life embodied and operational energy and CO2 emissions in Chinese residential buildings.

This paper identifies the need for Environmental Product Declarations (EPD) to provide End of Life (EoL) and Module D data for products for use in building level Life Cycle Assessment (LCA). Although the provision of data for EN 15804 Modules A4-D is not currently mandatory for EPD, many currently report some or all of these. This paper provides an overview of the existing reporting of the end of life (Modules C1-4) and Module D and the types of scenarios used in European EPD. Using examples from existing EPD for two product groups, this paper examines the variation in approaches to scenarios for Module C and D. It explores the difficulties brought by this variation and discusses benefits from using default national scenarios at end of life, but additionally considers the advantages of providing alternative EoL scenarios for products to promote the circular economy.

Promoting the decarbonisation of buildings requires effective policy measures. An integral part of policy design is ex-ante evaluation of possible policy options and effects. System Dynamics, one of a range of potential modelling paradigms, emphasises the dynamic complexity arising from stock-and-flow structures, feedbacks, non-linearities and time lags of the system in question. It is therefore well placed to model building stock turnover dynamics and the associated energy use and carbon emissions, in order to conduct scenario analysis for policy evaluation. Previous efforts to employ System Dynamics based models in buildings in various national contexts are found to have some common fundamental structural and behavioural limitations. We present an improved formulation that includes both building stock disaggregation and dynamics of energy-related retrofits. The model is characterised by greater transparency facilitating reproducibility and further improvements, high structural and functional flexibility for either extensions or reductions depending upon needs, and high generality and adaptability in diverse applications. It can be used as a stand-alone model or as part of a larger model for policy evaluation and scenario analysis exploring the transformation of building stock from improving energy efficiency and shifting towards low-carbon development.

The dominance of operational energy and related greenhouse gas (GHG) emissions of most existing build- ings is decreasing in new construction, when primary fossil energy of building operation decreases as re- sult of the implementation of energy efficiency measures as well as a decarbonisation of national energy mixes. Stakeholders therefore have a growing interest in understanding the possibilities for reducing em- bodied impacts in buildings. In the IEA EBC project ‘Annex 57’ a broad call for case studies was launched with the aim to identify design strategies for reducing embodied energy and GHG emissions (EEG) from buildings. The aim of this paper is to identify and provide a collected and comprehensive overview of quantitative reduction potentials of the particular EEG reduction strategies which should be considered by the stakeholders engaged in, and with the capacity to influence the outcome of, individual building projects. This is done by a systematic analysis of the Annex 57 case study collection as well as additional scientific literature. While it should be noted that the actual EEG savings at building level illustrated in this collection of studies are only applicable to each specific case, importantly this multiple cross-case analysis has provided rigorous evidence of the considerable potential to reduce embodied impacts in the design and construction of new and refurbished buildings.

This chapter explores the range of decisions and the reasons behind them when considering demolition and adaptation on a masterplan site in which multiple buildings are affected. It builds upon existing studies on adaptive reuse and demolition at an individual building level. The chapter identifies factors as drivers for decisions to demolish or adapt within masterplans include national and local policy, place-making and its link to economic viability, technical aspects, and phasing and market changes. Policy is a fundamental aspect of decision-making both at the individual building level and within the context of a larger scheme. The factors identified in the previous section will have varying levels of importance for the different stakeholders involved in the decision process.

The importance of embodied energy and embodied greenhouse gas emissions (EEG) from buildings is gaining increased interest within building sector initiatives and on a regulatory level. In spite of recent harmonisation efforts, reported results of EEG from building case studies display large variations in numerical results due to variations in the chosen indicators, data sources and both temporal and physical boundaries. The aim of this paper is to add value to existing EEG research knowledge by systematically explaining and analysing the methodological implications of the quantitative results obtained, thus providing a framework for reinterpretation and more effective comparison. The collection of over 80 international case studies developed within the International Energy Agency’s EBC Annex 57 research programme is used as the quantitative foundation to present a comprehensive analysis of the multiple interacting methodological parameters. The analysis of methodological parameters is structured by the stepwise methodological choices made in the building EEG assessment practice. Each of six assessment process steps involves one or more methodological choices relevant to the EEG results, and the combination potentials between these many parameters signifies a multitude of ways in which the outcome of EEG studies are affected.

This chapter provides a comprehensive overview of the state of the art on this subject within Europe. In order to do so, it draws on a cross-case analysis of over 60 European case studies, developed and analysed by the authors as part of the International Energy Agency Annex 57 project.

Our current generation strives to provide the next crucial stepping stone towards sustainable buildings, delivering energy efficiency measures without compromise in ways which are financially viable. Selecting and implementing simple energy efficiency measures (EEMs) to reduce energy use and become more sustainable can be straightforward. More complex measures are under continuous improvement and have a greater range of financial options. Making the right long-term choice is difficult and the United Kingdom (UK) market remains sceptical. The results of this paper show that risk and uncertainty are the two key factors that inhibit wholesale adoption of EEMs and as a result a new method of long-term assessment is proposed. The Energy Efficiency Value Matrix (EEVM) consists of the following functional drivers: Cost, Flexibility, Maintenance, Energy Saving and Product Sourcing. Under these headings a building owner may consider any EEM and make a more informed choice. From residential to commercial buildings,...

The current regulations to reduce energy consumption and greenhouse gas emissions (GHG) from buildings have focused on operational energy consumption. Thus legislation excludes measurement and reduction of the embodied energy and embodied GHG emissions over the building life cycle. Embodied impacts are a significant and growing proportion and it is increasingly recognised that the focus on reducing operational energy consumption needs to be accompanied by a parallel focus on reducing embodied impacts. Over the last six years the Annex 57 has addressed this issue, with researchers from 15 countries working together to develop a detailed understanding of the multiple calculation methods and the interpretation of their results. Based on an analysis of 80 case studies, Annex 57 showed various inconsistencies in current methodological approaches, which inhibit comparisons of results and difficult development of robust reduction strategies. Reinterpreting the studies through an understanding of the methodological differences enabled the cases to be used to demonstrate a number of important strategies for the reduction of embodied impacts. Annex 57 has also produced clear recommendations for uniform definitions and templates which improve the description of system boundaries, completeness of inventory and quality of data, and consequently the transparency of embodied impact assessments.

Circular economy is quickly gaining momentum across numerous research fields. The founding principles of circular economies lie in a different perspective on, and management of, resources under the idea that an ever-growing economic development and profitability can happen without an ever-growing pressure on the environment. As such, the built environment has a lot to contribute, being the sector with the greatest environmental impacts. However, the few existing cases of current research in the built environment from a circular economy perspective seem to have just replaced the 3R principle (reduce, reuse, recycle) with the new ‘buzz-word’. In this paper, we argue that a significantly different research approach is necessary if the circular economy is to keep up to its promise of being a new paradigm for sustainability. We therefore propose a framework to formulate building research from within a circular economy perspective. The framework is built around six pillars and acknowledges the key role of interdisciplinary research and that of both bottom-up and top-down initiatives to facilitate the transition to ‘circular’ buildings. Although theoretical in nature, the framework has been tested against current discourse about buildings and circular economies and it has proven a valuable tool to cluster existing initiatives and highlight missing interdisciplinary links. As such it can provide a valuable starting point to contribute to the theoretical foundations of building research from within the new paradigm of circular economies and also shape future research directions.

Life cycle assessment (LCA) is increasingly becoming a common technique to assess the embodied energy and carbon of buildings and their components over their life cycle. However, the vast majority of existing LCAs result in very definite, deterministic values which carry a false sense of certainty and can mislead decisions and judgments. This article tackles the lack of uncertainty analysis in LCAs of buildings by addressing the main causes for not undertaking this important activity. The research uses primary data for embodied energy collected from European manufacturers as a starting point. Such robust datasets are used as inputs for the stochastic modelling of uncertainty through Monte Carlo algorithms. Several groups of random samplings between 101 and 107 are tested under two scenarios: data are normally distributed (empirically verified) and data are uniformly distributed. Results show that the hypothesis on the data no longer influences the results after a high enough number of random samplings (104). This finding holds true both in terms of mean values and standard deviations and is also independent of the size of the life cycle inventory (LCI): it occurs in both large and small datasets. Findings from this research facilitate uncertainty analysis in LCA. By reducing significantly the amount of data necessary to infer information about uncertainty, a more widespread inclusion of uncertainty analysis in LCA can be encouraged in assessments from practitioners and academics alike.

This book charts the path toward high performance sustainable buildings and the smart dwellings of the future. The volume clearly explains the principles and practices of high performance design, the uses of building information modelling (BIM), and the materials and methods of smart construction. Power Systems, Architecture, Material Science, Civil Engineering and Information Systems are all given consideration, as interdisciplinary endeavours are at the heart of this green building revolution.

Embodied and whole life carbon of buildings are increasingly gaining attention. However, embodied carbon calculation is still far from being common practice for sustainability assessment of buildings. Some of its greatest difficulties lie with the long life span of buildings which implies a great unpredictability of future scenarios and high uncertainty of data. To help understand which life cycle stages should get the most attention when considering a building project, this chapter proposes a new visualisation method based on Sankey diagrams for whole life carbon that allows one to cluster the carbon emitted in each of the life cycle stages as identified in current BS 15978 standards. With the proposed method, the carbon figures can be further broken down to account for building assemblies and components. Additionally, the method is equally suitable to account for physical quantities of what is embedded in buildings and their components. As such it can supplement some units of existing assessment methods (e.g., metal depletion measured in mass units of Feeq) and turn it into mass units of embodied steel. With such new metric, a life cycle assessment would include knowledge on flows as well as quantities. Such information could then be linked to the building permanently and smartly to be updated when necessary as the building evolves, changes, and gets upgraded, building on the theoretical foundations of the shearing layers of buildings. As such, this information could be embedded within BIM which is fully suitable to store parametric details for each building component.

Cambridge is a historic city in the UK with an international reputation. The CB1 development is a major real estate regeneration project around the train station aiming to provide a gateway to the city. Once complete it will provide over 50,000 sq m of offices; 5,000 sq m of retail; 1,250 student units and 330 residential dwellings. When creating such a masterplan on a brown field site with multiple existing buildings and in a sensitive context, multiple decisions to demolish or adapt need to be made. This paper tracks the history of the CB1 development through a review of planning documentation and media articles, and through interviews with key stakeholders, including the developers, town planners, architects, engineers and local campaigners, identifying where and how key decisions relating to adaptation and demolition were made. The case study reveals complexities of decision-making in a real-world context. For example, for some of the existing buildings there were conflicting viewpoints about their future. The demolition of a Victorian terrace in favour of two new-build office blocks saw opposition from a local campaign group and the city councillors. However, the planning refusal was taken to appeal by the developers, who were then granted permission by the Planning Inspectorate. Arguments put forward included the lack of architectural significance, supported by the building not being listed and the public benefit brought about by demolition. The paper also explores the technical aspects associated with buildings which were demolished or retained through the creation and analysis of a database of existing and new buildings. The exploration builds upon international research analysing features that increase adaptation potential. Considering such aspects as, the condition of the building; floor to ceiling heights; standardised floor plates; and intangible values, such as architectural significance. The paper therefore assesses the CB1 development from both a technical and social perspective. The conclusions encourage actions to ensure holistic and sustainable decision-making in the future, recommending: the need for early stakeholder engagement; clarity on the strength of outline planning permission; and the recognition that heritage conservation and new build can both contribute to place-making. The paper also demonstrates the need for compromise, with inevitable conflicting viewpoints on a development of this scale.

The argument presented in this paper calls for an approach to flood infrastructure that considers not only the need for a technical perspective in design and construction but also a social perspective. As a result of climate change and changing weather patterns, it is predicted that more intense rainfall will be experienced, as well as rising sea levels, resulting in a greater number of people across the world becoming vulnerable to flood events. The need for flood alleviation infrastructure is therefore highly likely to increase. However industry professionals responsible for design and construction have often neglected to see flooding as a social problem; consequently they focus only on the technical and cost-effective, rather than the social end user orientated, aspects of their design solutions. This paper presents the preliminary findings from research that seeks to understand how the social value of flood alleviation schemes is interpreted and discussed. The results are derived from an examination of the Didsbury Flood Storage Basin Improvements scheme between April and August 2013 in Manchester, UK. A series of semi-structured interviews were conducted with both the community and those responsible for the design, delivery and construction of the scheme. The findings presented demonstrate how social value is articulated by both groups, and where a difference in interpretation and perspectives exists. These findings reinforce the argument that adopting a socially, as well as technically, considerate approach for future flood infrastructure design and construction is a necessity, as more communities around the world are exposed to the very real risk of flood events.

Recent studies have shown that the importance of embodied carbon is growing in relation to assessing the environmental impact of buildings. This paper investigates how designers are looking to tackle this, and the effectiveness of some of the methods chosen. Although a number of commercial and non-commercial organisations are developing in-house tools to calculate embodied carbon, these lack the flexibility to be adopted by a wide range of users as well as the efficiency required to be appealing to designers at the early stages of a design. An alternative to these stand-alone tools is offered through the functionality of Building Information Modelling (BIM) software, which is capable of incorporating embodied carbon assessments as part of the normal design process. The potential of plug-in tools to obtain embodied carbon data from suppliers is an area that remains to be explored further.

The built environment puts major pressure on the natural environment; its role in transitioning to a circular economy (CE) is therefore fundamental. However, current CE research tends to focus either on the macro-scale, such as eco-parks, or the micro-scale, such as manufactured products, with the risk of ignoring the additional impacts and potentials at the meso-scale of individual buildings. This article sets out to unpack the fundamental defining dimensions of a CE and frame them for CE studies for the built environment. A critical literature review forms the basis for identifying and framing such fundamental dimensions. Our contribution highlights the key roles of interdisciplinary research and of both bottom-up and top-down initiatives in facilitating the transition to ‘circular buildings’. The frame for reference has been used to capture current discourse on the sustainability of the built environment and has proved to be a valuable tool to cluster existing initiatives and highlight missing links for interdisciplinary endeavours. The article represents a contribution to the theoretical foundations of CE research in the built environment and a stepping stone to shape future research initiatives.

As operational impacts from buildings are reduced, embodied impacts are increasing. However, the latter are seldom calculated in the UK; when they are, they tend to be calculated after the building has been constructed, or are underestimated by considering only the initial materials stage. In 2010, the UK Government recommended that a standard methodology for calculating embodied impacts of buildings be developed for early stage design decisions. This was followed in 2011–12 by the publication of the European TC350 standards defining the ‘cradle to grave’ impact of buildings and products through a process Life Cycle Analysis.\ud \ud This paper describes a new whole life embodied carbon and energy of buildings (ECEB) tool, designed as a usable empirical-based approach for early stage design decisions for UK buildings. The tool complies where possible with the TC350 standards. Initial results for a simple masonry construction dwelling are given in terms of the percentage contribution of each life cycle stage. The main difficulty in obtaining these results is found to be the lack of data, and the paper suggests that the construction and manufacturing industries now have a responsibility to develop new data in order to support this task.

Of all industrial sectors, the built environment puts the most pressure on the natural environment, and in spite of significant efforts the International Energy Agency suggests that buildings-related emissions are on track to double by 2050. Whilst operational energy efficiency continues to receive significant attention by researchers, a less well-researched area is the assessment of embodied carbon in the built environment in order to understand where the greatest opportunities for its mitigation and reduction lie. This article approaches the body of academic knowledge on strategies to tackle embodied carbon (EC) and uses a systematic review of the available evidence to answer the following research question: how should we mitigate and reduce EC in the built environment? 102 journal articles have been reviewed systematically in the fields of embodied carbon mitigation and reduction, and life cycle assessment. In total, 17 mitigation strategies have been identified from within the existing literature which have been discussed through a meta-analysis on available data. Results reveal that no single mitigation strategy alone seems able to tackle the problem; rather, a pluralistic approach is necessary. The use of materials with lower EC, better design, an increased reuse of EC-intensive materials, and stronger policy drivers all emerged as key elements for a quicker transition to a low carbon built environment. The meta-analysis on 77 LCAs also shows an extremely incomplete and short-sighted approach to life cycle studies. Most studies only assess the manufacturing stages, often completely overlooking impacts occurring during the occupancy stage and at the end of life of the building. The LCA research community have the responsibility to address such shortcomings and work towards more complete and meaningful assessments.

Extended abstract In the Climate Change Act of 2008 the UK Government pledged to reduce carbon emissions by 80% by 2050. As one step towards this, regulations are being introduced requiring all new buildings to be ‘zero carbon’ by 2019. These are defined as buildings which emit net zero carbon during their operational lifetime. However, in order to meet the 80% target it is necessary to reduce the carbon emitted during the whole life-cycle of buildings, including that emitted during the manufacture of materials and components, and during the processes of construction, refurbishment and demolition. These elements make up the ‘embodied carbon’ of the building. This paper reviews the existing European and UK standards, methodologies, databases and software tools for the estimation of embodied energy and carbon of buildings. While there is currently no legislation requiring the calculation of embodied energy in buildings, voluntary standards are being developed by the European Committee for Standardisation Te...

The majority of carbon emissions arise from the built environment, a fact which has led to a global policy focus on reducing carbon and energy from buildings in use. However, research demonstrates that embodied carbon is also an increasingly significant proportion of the whole life impacts from buildings. Embodied carbon is not yet the subject of regulation, and although the CEN TC350 standards provide a methodology, there remains a significant variation in its measurement. This paper investigates some of the issues and difficulties that need to be addressed before widescale regulation can be enforced. The investigation uses a detailed case study of a low-energy school building, studied during its construction phase. The cradle-to-grave embodied impacts were modeled to the TC350 Standards using an innovative tool, and the operational impacts were modeled to incorporate future climate predictions. In spite of the care taken over data collection and the collective support of the process from all stakeholders, the study demonstrates a high level of uncertainty in results, resulting from industry-wide barriers to embodied carbon measurement. Key recommendations are made for industry and policy, in order to overcome the current barriers and enable more accurate and comparable measurement of the embodied carbon of buildings.

The argument presented in this paper calls for an approach to flood infrastructure that considers not only the need for a technical perspective in design and construction but also a social perspective. As a result of climate change and changing weather patterns, it is predicted that more intense rainfall will be experienced, as well as rising sea levels, resulting in a greater number of people across the world becoming vulnerable to flood events. The need for flood alleviation infrastructure is therefore highly likely to increase. However industry professionals responsible for design and construction have often neglected to see flooding as a social problem; consequently they focus only on the technical and costeffective, rather than the social end user orientated, aspects of their design solutions. This paper presents the preliminary findings from research that seeks to understand how the social value of flood alleviation schemes is interpreted and discussed. The results are derived from an examination of the Didsbury Flood Storage Basin Improvements scheme between April and August 2013 in Manchester, UK. A series of semi-structured interviews were conducted with both the community and those responsible for the design, delivery and construction of the scheme. The findings presented demonstrate how social value is articulated by both groups, and where a difference in interpretation and perspectives exists. These findings reinforce the argument that adopting a socially, as well as technically, considerate approach for future flood infrastructure design and construction is a necessity, as more communities around the world are exposed to the very real risk of flood events.

This paper introduces the IEA Annex 57 case study method, consisting of a format for describing individual case studies and an evaluation matrix covering all case studies. Sample case studies are used to illustrate the method and the evaluation matrix through a first preliminary analysis. In compiling and evaluation existing, transparent case studies we have taken a stakeholder perspective. By so doing it is intended to identify fordecision makers the key issues affecting EE/EC in buildings. Analysis in this paper focuses on one of the six case study themes, building design strategies for EE/EC mitigation and references cases covering e.g. material selection, building shape, construction stage strategies and strategies to handle the trade-off between embodied and operational impacts in net-zero emission building design.