Meeting pressing carbon emission reduction targets successfully will require a major shift in the performance of buildings. The complexity of the building stock, the importance of buildings in people's lives, and the wide spectrum of agents responsible all make buildings an important area of 'policy resistance'. Policies may fail to achieve their intended objective, or even worsen desired outcomes, because of limitations in our understanding of the building stock as a dynamically complex system. This limitation can lead to 'unintended consequences' across a range of outcomes. The concept of the 'performance gap' with regards to the energy performance of buildings is now well established and useful work to begin to understand this challenging issue has been undertaken. However, potential unintended consequences related to the inter-linked issues of energy/Indoor Environmental Quality (IEQ) present an even greater and more complex challenge - a challenge that is gaining increasing importance in the UK and China. There are exciting opportunities to address this issue of 'total performance' in order to reduce the energy demand and carbon emissions of buildings whilst safeguarding productivity and health. Our work will begin by examining the contrasting context within which buildings have been designed and constructed and within which they are used and operated internationally. We will address the policies and regulatory regimes that relate to energy/IEQ but also the assessment techniques used and the ways that buildings are utilised. We will then build on this analysis by undertaking an initial monitoring campaign in both countries to allow comparisons between the performance of the same types of building in the two different contexts. We will evaluate how energy/IEQ performance varies between building type and country. This work will enable the assembly of a unique database relating to the interlinked performance gaps. This initial monitoring work will also allow us to identify the most suitable buildings for the next stage of the work that will integrate monitoring and modelling approaches. This phase of the work will develop semi-automated building assessment methods, technologies and tools to enable rapid characterisation of probable pathologies to determine the most cost-effective route to remedy the underlying root causes of energy/IEQ underperformance. Energy/IEQ issues do not form a closed system however. In the development of relevant policies and regulations, it is vital to consider the wider system and we propose a second stream of work to address this. The team at UCL has undertaken pilot work within the housing sector as part of the EPSRC funded Platform Grant ('The unintended consequences of decarbonising the built environment'). We successfully employed a participatory system dynamics approach with a team of over 50 stakeholders and we will extend that work here to other building typologies. Such an approach can help support decision-making in complex systems, addressing challenges central to the TOP work. The proposed work is tremendously challenging and exciting. If successful it will lead the way in understanding and improving the total performance of low carbon buildings and help to develop relevant effective policies and regulations in the transition towards future Low Carbon Cities. Tsinghua and UCL have the suitable complementary world-leading expertise to undertake this work and form a long-term 'best with best' academic collaboration. The Bartlett at UCL is rated first in terms of research 'power' and environment in the UK; the Tsinghua University School of Architecture was ranked first in China in the National Assessment on Architecture in 2003, 2008, and 2011. The groups in both countries have extensive stakeholder networks and the outputs of the project will thus be communicated widely and appropriately.

As we age, many of us will experience cognitive changes, and for some of us, these will develop into dementia. We know that people's homes can make the experience of cognitive changes more difficult, or can enable continuing inclusion and sense of self-worth and self-esteem. DesHCA will work with people experiencing ageing and cognitive change and those who design and develop housing. We will identify housing innovations that can support living better for longer with cognitive change. Our emphasis on healthy cognitive ageing goes beyond narrow conceptions of 'dementia-friendly design' into a more expansive and inclusive approach to housing innovation. The multidisciplinary DesHCA team involves stakeholders from all areas of housing provision, including people experiencing ageing and cognitive change, architects and designers, housing experts, planners, builders and housing providers. Older people are integral to DesHCA and their health is at its heart. The project will design and build virtual and real designs that will act as demonstrators and test-beds for innovations to support healthy cognitive ageing. These designs will be evaluated from stakeholder points of view, then considered at a larger scale to examine their real-world feasibility. DesHCA has a unique opportunity to feed directly into the UK and Scottish Government City Region Deal for Central Scotland (Stirling and Clackmannanshire), providing groundwork for local housing developments. The focus of this is sustainable, lifetime health, community and economic development, addressing deprivation and inequality. To achieve these aims, DesHCA takes a co-production approach, with the whole team working to identify innovations that engage with their real-world experiences and aspirations. We will use exciting and involving ways to collect data which will be used to inform the design of the demonstrator houses. These designs will evolve as stakeholders interact with them and provide feedback from their different points of view. To collect data, we will ask older people to map and evaluate their own homes and to experience and comment on new design features using virtual reality (VR). They will then collaborate with builders, architects and housing providers in VR workshops to identify practical, realistic and affordable designs that can support healthy cognitive ageing, and therefore longer healthy, independent life. Partners will then come together in interactive workshops to convert designs into plans within a fictional town, building and retrofitting homes, creating services and managing budgets. We will demonstrate how designs can work out in the real world, and how to bring together the various interests involved. Throughout, we will consider issues of costs, to inform business planning and help make decisions on implementation of the new designs. The impact of DesHCA will be achieved through showing what works in housing design for healthy cognitive ageing. Immediately, DesHCA will feed into the City Region Deal and longer term we will provide tools for future developers to inform their decisions about housing for healthy cognitive ageing. Throughout the project, we will disseminate findings to the housing, architecture and building sectors through stakeholder networks. We will publish rigorous research findings to provide a peer reviewed, high quality research base for innovation. Thus we will go beyond recommendations and guidance to provide evidence to support delivery at scale, grounded in the co-production approach that draws on the real experience, interests and imperatives that drive different stakeholders. DesHCA's multidisciplinary team will build capacity among early career researchers in research leadership, working across disciplines such as architecture and planning, economics, sociology and across sectors with a range of different industrial and professional stakeholders, such as housing workers, planners and construction companies.