LoHCool focuses on topic T1 'Delivering economic and energy-efficient heating and cooling to city areas of different population densities and climates'. It confronts directly the conundrum of offering greater winter and summer comfort in a Continental climate zone whilst mitigating what would be a carbon penalty of prodigious proportions. It concentrates on recovering value from the existing building stock, some 3.4 Billion m2 in which dwell and work some 550 Million citizens. It is highly cross-disciplinary involving engineers, building scientists, atmospheric scientists, architects and behavioural researchers in China and UK measuring real performance in new and particularly in existing buildings in Chinese cities to investigate the use of passive and active systems within integrated design and re-engineering. It focuses on the very challenging dynamic within China's Hot Summer/Cold Winter HSCW climate zone. It aims to enable the much desired improvements in living conditions and comfort levels within buildings through developing a keen understanding of the current heating and cooling technologies and practices in buildings by monitoring, surveying and measuring people's comfort and capturing this understanding through developing systems modelling including energy simulations. It will borrow on UK research for comparative purposes, for example work examining the current and future environmental conditions within the whole National Health Service (NHS) Hospital Estate in England and the practical economic opportunities, very considerable, for significant improvement whilst saving carbon at the rate required by ambitious NHS targets. It will propose detailed practical and economic low and very low carbon options for re-engineering the dominant building types which we will identify in a series of cities, as developed with local stakeholders, contractors and building professionals, exploring economic and energy-efficient low carbon district heating and cooling systems. Finally, it will test them in the current climate, 'current' extreme events, future climates and will estimate the carbon implications and cost of widespread implementation. Findings for the existing stock will be equally applicable to new-build, in many ways a simpler prospect.

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.