Buildings: The new energy nexus

Abstract Buildings are the largest contributors to households' energy footprints. If both the energy for household mobility and the embodied energy are added to the energy for heating/cooling, domestic hot water, lighting, buildings are by far the main problem of energy consumption in France. This paper presents a review of the evolution of the main drivers of CO 2 emissions by buildings in France. Eventually, the paradox of the effect of density is discussed. Lower density of cities increases the energy spent per inhabitant, in particular for transport, but may also increase the production of low-carbon renewable energies, shifting the global energy balance and influencing the prospective studies of future, energy efficient, smart cities.