In the UK retail outlets are the biggest emitters of CO2 within the commercial property sector. Many retail business are striving to reduce their carbon footprints, with many having ambitious targets for carbon neutrality over the next few years. This feasibility study aims to identify new ways to dramtically reduce end use energy demand within the retail sector. The novelty of the proposed work lies both in its scope and the technologies that it will develop. Rather than attributing energy use and human comfort directly to spatial design, building services, energy controls, company energy policy or human behaviour, this research will explore the intersection of all of these influences within a 'mixed reality' retail environment. This would take the form of an interactive 'gaming' model as a portable 'box' with a tangible user interface deployed in store. It would allow users to 'visualise' energy use and its consequences as part of a broader energy engagement strategy. The box would comprise a scale model of a physical store layout and a set of coded intervention cards that would allow participants to interact with the physical model on the table as well as in the virtual model - the blend between physical and virtual interactions establishes a mixed reality design platform (MRDP). Real time data from existing store sensors can feed directly into the virtual model to inform and respond to scenario testing as users interact with the model. Store staff and customers would be able to engage with the model proactively or passively via a mix of physical, virtual and display modules. This serious gaming environment will provide a stimulating and interactive way of sharing ideas and co-creating new solutions. Most importantly, the MRDP transforms what is normally an intangible numerical database (numbers collected by performance sensors) into an interactive and immersive experience to allow for continual testing and refinement with the opportunity of users co-creating novel approaches to reducing energy use while maintaining a positive shopping experience. The learning that accrues through this serious gaming activity would inform future strategies for reducing energy demand whilst simultaneously attending to other performance criteria (e.g. internal air quality, thermal comfort and the customer experience). The mobility and placement of the MRDP allows the retail floor or back of house area to become a platform for learning and drives a more open relationship with stakeholders. Our principal research partner is Tesco PLC, the UK's largest retailer with revenue of over £55 Billion. Tesco have an ambitious commitment to become a zero carbon business by 2050, and as part of this they aim to reduce carbon emissions in store by 50% over the next 4 years. This research would support their objectives by developing an exciting method of accelerating their progress towards their corporate goal and will help position the organisation at the vanguard of current technology and thinking in the energy demand reduction space.

The first Complex Built Environment Systems (CBES) Platform Grant consolidated a truly interdisciplinary, world-leading research group which focussed on the complexity of the context of our research activities and seeded a new Institute (UCL Energy). The second Platform Grant underpinned the development of a strategic programme of fundamental research aimed at understanding the unintended consequences of decarbonising the built environment, enabled CBES to become a world leader in this area and seeded three new UCL Institutes (Environmental Design & Engineering, Sustainable Heritage and Sustainable Resources). Supported by a third Platform Grant, our vision for CBES is now to transform scientific understanding of the systemic nature of a sustainable built environment. In a recent award-winning paper, resulting from our work under the current Platform Grant, we identified over 100 unintended consequences of energy efficiency interventions in homes. Taking moisture as just one example, we can demonstrate why a systems thinking approach is now so vital. By 2030, it will be government policy that every home in the UK will benefit from measures to improve energy efficiency. This is approximately 25 million homes - all our homes will be affected in some way. The total cost will be ~ £10 billion a year. The UK only has the chance once to do this correctly. Unfortunately, it is now clear that we are not dealing with these complex issues correctly. For example, a recent low energy refurbishment of ~400 dwellings in the north of England has had a 100% failure rate due to disastrous moisture issues which will cost millions to rectify. This has huge implications for the entire decarbonisation plan, for the health of the building occupants, for the communities involved and for the economic value of these properties. For the issue of moisture therefore, we have taken the decisive step to set up the new 'UK Centre for Moisture in Buildings' to link building engineering physics, health, building use, quality and process in a coherent way. Our thesis therefore, more widely, is that the built environment is a complex system that can only be successfully tackled via a new interdisciplinary systems thinking approach - performance emerges from the interplay of fundamental engineering and physical factors with process and structure. Such a systems thinking process was piloted in our project 'Housing, Energy and Wellbeing' (HEW) in the current Platform Grant and has led to close collaboration with a very large body of stakeholders from government, industry, NGOs and community groups who provide an invaluable resource for future research. Enabling this new, systemically integrated approach to built environment research will require a major change in the way we undertake our research - this will be a fundamental departure from business as usual. The development of such a novel methodological framework and the associated re-structuring and development of an interdisciplinary research group will involve a strategic, long-term perspective as well as some risk. The flexible Platform funding will be vital here in that it will enable approaches not possible with responsive mode funding. There are also likely to be some key policy changes in this specific area over the next 5 years - Platform funding will enable us to react to research opportunities in a timely manner and dynamically maintain research leadership in the field. The careers of CBES team members will be managed and developed through strategic action. Career development activities specifically enabled by Platform funding will include: (i) a new series of regular 'systems thinking' workshops to develop personal research agendas within our broader system of research; (ii) new industrial/policy mentoring via secondments; (iii) new skills training for staff through external training courses; (iv) enhanced stakeholder engagement via our unique series of regular workshops.

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.