UHI phenomenon with higher compatibilities in cool pavement and green infrastructures. Although there are some intrinsic discrepancies among understandings of sponge city and UHI mitigation towards blue infrastructure, the osmotic pool, wet pond, and regulating pond are essential supplements to urban water bodies, performing their roles in nourishing vegetation and evaporating for cooling in UHI mitigation. Sponge city pilot projects have already provided the financial foundation for taking the UHI mitigation further. It is an attempt for people in different disciplines to synergistically think about how to mitigate UHI effects, which is conducive to the generation of holistic policies, guidelines and regulations. Furthermore, the inclusion of UHI mitigation can be a driver to public participation in sponge city construction, which can consolidate the PPP model for more funds. The weights of different authorities can also be redistributed to promote institutional transitions. Green building programs Voluntary green building programs have been promoting the mitigation of the heat island effect for years. For example, one of the ways for a site to earn points under the US Green Building Council's (USGBC) Leadership in Energy and Environmental Design (LEED) Green Building Rating System is to take action that reduces heat islands, minimizing impacts on microclimates and human and wildlife habitats. Credits associated with reflective roofing or planted roofs can help a building achieve LEED certification. Buildings also receive credits by providing shade. Similarly, The Green Building Initiative's Green Globes program awards points to sites that take measures to decrease a building's energy consumption and reduce the heat island effect. As many as 10 points may be awarded to sites with roof coverage from vegetation, highly reflective materials, or a combination of the two. Moreover, some scholars advocate that microclimate moderation should be included to foster, or at least be harmless to, the initial goals of GB in energy consumption reduction, carbon emission reduction and indoor environmental quality. Based on this, they argue the next generation of green building should be GB-based UHI mitigation system, or ‘zero UHI impact building’, or ‘zero-heat building’ or ‘microclimate neutral building’, aiming to achieve the zero-heat impact on surrounding environments through reasonably designing and operating buildings, or depending on innovative techniques to eliminate the excessive heats, on the basis of GB's goals. Cost analysis Every year in the U.S. 15% of energy goes towards the air conditioning of buildings in these urban heat islands. According to Rosenfeld et