How can the city be built for the climate? For Nantes Métropole, the public body responsible for inter-municipal cooperation and urban and climate policy, this question is still highly relevant. Despite being a pioneer in France in the fight against climate change, Nantes' climatic, geographic and urban situation have led urban and climate issues separated, albeit by a fine line. The prospect of climate change requires a reconsideration of how the city is built. This must be based, in particular, on two inter-related questions: Do we know how to build the city for the current climate? Followed by, will we know to build the city for the climate of tomorrow?The approach of the climate Plan (Plan climat) being implemented in Nantes and the partnerships formed with local research institutions provide us with some of the initial answers to these questions. With regard to the current climate, research projects on bioclimatic design have been carried out at district level. For the climate of tomorrow, research on vegetation and greening strategies will help us to address the urban heat island issue more successfully.However Nantes' experiments have revealed certain limitations concerning, for example, whether the approach could be applied elsewhere, and how research expertise can be transferred to the practical field of urban engineering. These new problems highlight a need to bridge the gap between researchers and planning professionals to ensure that urban heat islands are dealt with in a concrete and pragmatic manner at local level.