The buildings we live in, work in, and shop in all contribute to the UK's carbon emissions. In fact, they account for more than 40% of the total national emissions. These emissions can be divided between operational and embodied emissions. The operational emissions are those related to running the building (e.g. heating, lighting) whereas the embodied emissions are those occurred in every activity necessary to extract and manufacture the raw materials, transport them on site, and assemble and maintain them up to the end of life disposal. Embodied carbon emissions have a peculiar characteristic: once they have been emitted in the atmosphere there is no way back. Any intervention, even if beneficial in the future, instantly provokes an increase of the embodied carbon. This is why embodied carbon is so important: we need to reduce embodied emissions now or we simply will not be able to do it in the future. The majority of the embodied emissions in buildings are often related to the building structure. This is because the structure generally takes up most of the building's total mass, and it is often made of materials that require a lot of energy (and therefore emit a lot of carbon) to be produced. It is therefore imperative to measure correctly the embodied carbon of building structures, in order to understand where the opportunities for carbon mitigation are and how to access the untapped reduction potential. The project will seek to answer the following questions: I. How do different materials affect the whole life carbon emissions of building structures? II. What are the whole life carbon emissions of building structures for different building types in the UK? This project will establish how different structural materials affect the whole life carbon emissions of building structures through rigorous numerical assessments across the main building types in the UK (i.e. residential, non-domestic). This shall move us away from the current 'sentimental' discourse over how green a material is to allow to choose the material with the lowest environmental impact over a building's life cycle for the specific project at hand. The aim is not therefore to promote one material over the others but rather to allow for informed decisions based on comparable assessments of the different materials by looking at the correct comparative unit, i.e. the building structure within a given building type. The project will collect primary data from industry where no robust information is available on the carbon emissions of the different materials across their whole life cycle, and will adopt stochastic modelling and uncertainty analysis to produce probability distributions of the likely carbon emissions. This will contribute to superseding the current deterministic mind-set, which results in single-value assessments that are of very little use. The findings will be published as guidance to architects and designers, planners and policy-makers, and in the professional press, as well as in academic papers.

The built environment is estimated to account for around 50% of all carbon emissions. About 10% of global GDP is generated by the construction industry, which creates and maintains our built environment. Recent success in reducing operational energy consumption and the introduction of strict targets for near-zero energy buildings mean that the embodied energy will soon approach 100% of total energy consumption. The importance of this fundamental shift in focus is highlighted by the analysis of recently constructed steel and concrete buildings, in which it was demonstrated that embodied energy wastage in the order of 50% is common. Inefficient over-design of buildings and infrastructure must be tackled to minimise embodied energy demand and to meet future energy efficiency targets. The UK Government has set out its ambition to achieve 50% lower emissions, 33% lower costs, and 50% faster delivery in construction by 2025. These ambitious targets must be met at the same time as the global construction market is expected to grow in value by over 70%. Achieving growth and minimising embodied energy will require a step change in procurement, design and construction that puts embodied energy at the centre of a holistic whole-life cycle design process. The global population is expected to grow to 9.7billion by 2050, with 67% of us living in cities. China alone will add 350 million people to its urban population by 2030. Yet Europe's and Japan's population will both be smaller in 2060 than they are today, and the total population of China is expected to fall by 400million between 2030 and 2100. Depopulation of cities will occur alongside reductions in total populations for some countries. This presents a complex problem for the design of the built environment in which buildings and infrastructure constructed today are expected to be in use for 60-120 years: providing structures that are resilient, healthy, and productive in the medium term, but demountable and potentially reusable in the long term. The targeted feasibility studies of this proposal will be vital in ensuring that this can be achieved. We have identified a series of areas where feasibility studies are essential to define research needs to enable significant energy savings in the construction industry before 2025. We will identify a series of 'low-hanging fruit' research areas, in priority order, for embodied energy savings, and work with our industrial partners to develop feasible pathways to implementation in the construction industry.

The built environment is estimated to account for around 50% of all carbon emissions. About 10% of global GDP is generated by the construction industry, which creates and maintains our built environment. Recent success in reducing operational energy consumption and the introduction of strict targets for near-zero energy buildings mean that the embodied energy will soon approach 100% of total energy consumption. The importance of this fundamental shift in focus is highlighted by the analysis of recently constructed steel and concrete buildings, in which it was demonstrated that embodied energy wastage in the order of 50% is common. Inefficient over-design of buildings and infrastructure must be tackled to minimise embodied energy demand and to meet future energy efficiency targets. The UK Government has set out its ambition to achieve 50% lower emissions, 33% lower costs, and 50% faster delivery in construction by 2025. These ambitious targets must be met at the same time as the global construction market is expected to grow in value by over 70%. Achieving growth and minimising embodied energy will require a step change in procurement, design and construction that puts embodied energy at the centre of a holistic whole-life cycle design process. The global population is expected to grow to 9.7billion by 2050, with 67% of us living in cities. China alone will add 350 million people to its urban population by 2030. Yet Europe's and Japan's population will both be smaller in 2060 than they are today, and the total population of China is expected to fall by 400million between 2030 and 2100. Depopulation of cities will occur alongside reductions in total populations for some countries. This presents a complex problem for the design of the built environment in which buildings and infrastructure constructed today are expected to be in use for 60-120 years: providing structures that are resilient, healthy, and productive in the medium term, but demountable and potentially reusable in the long term. The targeted feasibility studies of this proposal will be vital in ensuring that this can be achieved. We have identified a series of areas where feasibility studies are essential to define research needs to enable significant energy savings in the construction industry before 2025. We will identify a series of 'low-hanging fruit' research areas, in priority order, for embodied energy savings, and work with our industrial partners to develop feasible pathways to implementation in the construction industry.

Although there are many issues facing the built environment, decarbonisation is THE central challenge: The UK has the stated aim of an 80% cut in carbon emissions by 2050. This target can only be met if we transform society. The built environment is responsible for 50% of relevant emissions, making it the largest single emitter, and therefore it will need to be near fully decarbonised by that date. The Department of Architecture and Civil Engineering together with the Departments of Mech. Eng., Psychology, Computer Science and Maths at the University of Bath propose a Centre for Doctoral Training (CDT) in the Decarbonisation of the Built Environment. The £3.5m requested from the EPSRC will be leveraged by £6m from the University and at least £1.3m for industrial partners to fund a CDT operating at the interface of Architecture, Building Science, Social Science and Computing. The CDT will place the fundamental need of society to decarbonise at the core of a broad spectrum of research and training. A dynamic, multidisciplinary research and training environment (the combined research income since 2008 of the 7 departments is >£60m (£22.8m from EPSRC)) will underpin transformative research and training in the built environment. This will respond to a national and global need for highly skilled and talented scientists and engineers in the area, as evidenced by a recent report by the Royal Academy of Engineering, and as testified to by our key industrial partners. This, multidisciplinary, Centre has three aims, all centred on aiding this rapid decarbonisation: (i) to further the UK research agenda on sustainable building design including retrofit, materials and energy in-use; (ii) train the next generation of research-led engineering leaders and architects that will enter the construction profession through the UK's major engineering companies and architectural firms; (iii) help provide the next generation of academics who will have prime influence in this field from 2020 onwards. All students will receive cohort-based foundation training to supplement their original undergraduate or masters knowledge, as well as training in the post-carbon built environment and transferable skills. They will all conduct high quality and challenging research within EPSRC's Sustainable Built Environments priority area and be directed by joint supervision from different disciplines within the CDT and other departments where necessary. The broad research themes encompass the areas of: materials; building physics; construction management; control; social science; resilience to climate change, economics and architecture. Participation from key industry partners will address stakeholder needs, and partner institutions such as the Building Research Establishment, Arup, Atkins, Buro Happold, Arup, Feilden Clegg Bradley Studios, Lhoist, Expedition will provide world-leading external input, along with meaningful opportunities for student placements. Detailed management plans have been developed in order to facilitate the smooth running of the centre and to enable excellence in the training and research aspects of the proposal. The CDT will be supported by the creation of physical and virtual laboratories for the students. This initiative has attracted strong and influential support: "Within this field, decarbonisation is a crucial factor for our clients" and "There is no doubt in my mind that Bath University is the right place for such a Centre......it is the best of the multi-disciplinary schools in the country that allows people to bridge between the traditional disciplines" Michael Cook, Chairman Buro Happold. (See letters of support.)

Cement manufacture accounts for about 5% of global carbon dioxide emissions, the single largest contribution of any man-made material. Despite this, research has shown that concrete is generally inefficiently used in the built environment. This fellowship will look to reduce the global environmental impact of concrete construction through a new method for the analysis of reinforced concrete structures that is well suited to producing the optimised designs that have the potential to significantly reduce material consumption. The new analysis method will be considered alongside practical construction processes, building on previous work by Dr Orr in this field, thus ensuring that the computationally optimised form can actually be built, and the research adopted, in industry. Most existing computational methods poorly predict the real behaviour of concrete structures, because their underlying mathematics assumes that the structure being analysed remains continuous as it deforms, yet a fundamental property of concrete is that it cracks (i.e. it does not remain continuous as it deforms). In contrast to finite element methods, this fellowship will develop a meshfree analysis process for concrete based on 'peridynamics'. The term 'peridynamic' (from 'near' and 'force') was coined by Dr Silling (see also statements of support) to describe meshfree analysis methods in solids. This new approach does not presume a continuous displacement field and instead models solid materials as a collection of particles held together by tiny forces, the value of which is a function of each particle's relative position. Displacement of a particle follows Newton's laws of motion, and is well suited to reinforced concrete since: 1) concrete really is a random arrangement of cement and aggregate particles; 2) failure is governed by tensile strain criteria, which is ideal as the only real way that concrete fails is in tension (all other failure modes in everyday design situations are a consequence of tensile failure) and the model can therefore accurately predict behaviour, and 3) since the elements fail progressively in tension, the peridynamic approach automatically models cracking behaviour, which is extremely difficult to model conventionally. A variety of force-displacement relationships can be defined to model the concrete, the reinforcement, and the reinforcement-concrete bond that together define the overall material response. The approach models the material as a massively redundant three-dimensional truss in which the randomly arranged particles are interconnected by elements of varying length. Although an optimal 'element density' has not yet been determined (see Section 2.4.1 in the case for support) proof of concept work has used tens of millions of particles and hundreds of millions of elements per cubic metre of concrete. From the simple rules and properties applied to these elements, all the complex behaviour of concrete can be predicted. Individual element definitions will be determined by laboratory tests and computational analysis, with both historic and new test data utilised. Crucially, the model has been shown in proof-of-concept work to be able to predict the cracking behaviour of concrete, overcoming a key computational challenge. Optimisation routines, in which material is placed only where it is needed, will then be integrated with the new analysis model to design low-carbon concrete structures. Consideration of the practical construction methods will also be given, building on previous work in this area by Dr Orr. The designs that result from such optimisation processes will have unconventional but completely buildable geometries (as evidenced in Dr Orr's previous work) - making them ideal for analysis using the proposed random elements approach.