Efficacité énergétique et formes urbaines : élaboration d’un outil d’optimisation morpho-énergétique

This paper deals with the link between urban forms and energy balance. Nowadays, many French urban planners recommend dense and compact cities to suit the imperatives of sustainable development. Dense cities are usually said to consume little energy and space, contrarily to more spread out cities. In the last twenty years, many studies showed the compactness of a building can impact its heating loads: the more compact the building, the lower its heating consumption is. But, this relationship between form and energy is less obvious on a city-wide scale since the forms and morphologies of cities are complex. First of all, this paper presents the urban and scientific context our study is relating to. It concludes that a change of scale is necessary to suit energy efficient (pieces of) cities with "reasoned" urban density. Then our research is divided into two parts. The first one introduces the issue of density distributions by analysing the energy efficiency of six archetypal urban forms that have the same density. The second one deals with the main study of our research: the morphogenesis of a piece of city thanks to a genetic algorithm optimisation process considering three parameters: density of population, energy performance and sun penetration. Finally, the results are detailed, aiming at discussing advantages and limits of such a micro-urban morphogenesis method