The process of residential energy retrofitting needs to be advanced, especially in the hot summer and cold winter (HSCW) zone of China. Good cooperation from homeowners is the key to the smooth project implementation. Some studies have identified four categories of information as important factors affecting homeowners' decision-making in retrofitting. Such information can improve homeowners' cooperation to some extent. This paper investigates the nature of this influence mechanism of retrofitting information, so as to stimulate homeowners' cooperation. The authors, first, explain how the direct relationship between information and homeowners' level of cooperation is validated. Second, under the mediation role of risk perception, we verify the indirect influence of such information. Third, we analyse the variation in the strength of the relationships between information and homeowners' cooperation under the influence of source credibility. It is concluded that providing information on retrofitting benefits and service is more effective for improving homeowners’ cooperation. The integrity of building quality information and the understandability, to the homeowners, of technology information need to be considered. Priority should be given to the sources of expert knowledge and published resources, because they are perceived by homeowners to be relatively credible. Policy suggestions are proposed based on the results.@en

Energy retrofit of residential buildings is an approach to reduce worldwide energy consumption. Residential energy retrofitting in China mostly focuses on multi-owner residential buildings with composite ownership that dozens of private homeowners own their apartment and jointly own the common parts of a building. The implementation of residential energy retrofit faces many risks, causing the slow retrofit process in the hot summer and cold winter (HSCW) zone of China. Transaction cost theory (TCT) is conducive to enrich an in-depth understanding of risk inventories in the energy retrofitting context. This paper aims to explore the key risks in retrofit projects of residential buildings in the HSCW zone with transaction costs (TCs) considerations, in order to provide the direction for effective risk management. First, based on the theoretical risks with TCs considerations, interviews were conducted to adjust the risk list and to connect these risks with stakeholders and stages. Second, a questionnaire survey was made based on two parameters of risk probability and severity, and then ten top risks were chosen as key risks through both a risk matrix and Borda count. The results show that most of the key risks are associated with homeowners and contractors, involving retrofit awareness, cooperation performance, opportunism, professional expertise, construction management, safety management, and maintenance, of which most occur at the stage of on-site construction. Information cost is the largest source of TCs relevant to these key risks and is mainly borne by the government and homeowners. TCs can also provide a lens for the retrofitting in other countries to understand risks, and the decrease in information costs contributes to effective risk management both in China and in the international context.

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To speed up residential energy retrofitting in the Hot Summer and Cold Winter(HSCW) zone, the barriers to retrofitting projects need elimination. Energy retrofitting contributes to improving building quality and living comfort, but has not been accepted by the public. It stems from poor project performance in quality, time, costs, etc. The risk is an essential factor hindering such project objectives and project success. Residential energy retrofitting in China is exposed to various risks due to uncertainties regarding finance, organization, coordination, technology, etc. This thesis thus aims to deepen the understanding of risks in the whole process of residential energy retrofitting to smoothen its implementation and develop risk mitigation strategies for the HSCW climate zone of China. The thesis adopts Transaction Costs Theory (TCT) to identify the risks in the whole process of project implementation and assesses the importance of these risks in both objective and subjective aspects. Given the importance of homeowners-related risks and the key role of the government in retrofitting projects, this research develops s series of develop strategies for risk mitigation from the viewpoints of both homeowners and the government. The thesis contributes to the body of knowledge by conducting a systematic exploration of risks in retrofitting projects. In terms of the practical contributions, it does not only enable project managers to recognize the priority of project risks, but also help the government tackle these issues at its source for promotion of residential energy retrofitting. @en

The implementation of energy retrofit of residential buildings faces many risks around the world, especially in China, leading to low retrofit progress. Stakeholders’ proactive risk management is the key to the smooth implementation of retrofit projects but is normally affected by risk perception. Perceived risks instead of real risks are the motivators of their proactive behaviours. This paper aims to understand and address the present risk perception of stakeholders in order to drive effective proactive risk mitigation practices. Based on a risk list identified through a literature review and interviews, a questionnaire survey was then made to analyse and compare different stakeholders’ perceptions of each risk by measuring the levels of their concern about risks. It is validated that all the stakeholder groups tend to mitigate risks perceived highly proactively. Proactive risk management of risk-source-related stakeholders deserves more attention and responsibility-sharing with transaction costs (TCs) considerations contribute to the enhancement of risk perception. More responsibilities of construction quality and maintenance is taken by the government and contractors should be clarified, and the government should also be responsible for assisting design work. Effective information is beneficial to the decrease in homeowners’ risk perception that can motivate their initiative of cooperation.@en

In China, majority of residential buildings constructed before 2000 remain poor energy performances due to few regulations on energy conservation before 2000. Thus there is a great potential for energy savings in China’s residential buildings. However, in the current situation it is difficult to this make full use of this energy saving potential. The development of housing energy retrofitting (HER) in China is still slow due to risks, such as unexpected payback period, reliability issues, etc. Some of risks are due to bounded rationality and opportunism, which induces TCs, such as information searching cost, negotiation cost, etc., in HRE projects. This study aims to investigate risks of HER projects from planning to operation with TCs considerations. First, literature on the status quo of housing energy retrofitting in China will be reviewed; Second, this study will review on the generic risks of HER collected from international projects and apply TCs theory to reveal the hidden risks during HER process; Third, it will propose a risk framework with TCs considerations for China by relating the risks to the stage/stakeholders in China, for future empirical study.@en