Supplying energy to a business park is a lever towards sustainable development of an area. Communities have understood this and take the advice of the experts before making big decisions. Bordeaux Métropole launched an advance study on the energy servicing for the future Bastide Niel urban development zone to adapt the layout of 250 hectares of derelict ground on which 300 000m2 of buildings are planned, half of which will be accommodation. This study was carried out even before consulting the town planner. Cap Ingelec carried out investigation and modelling work considering a certain number of hypotheses regarding the energy performance and quality of the planned buildings, and defining the needs in heating, cooling and electricity, in order to find the best answers. Cap Ingelec weighed up the costs and the benefits. These ambitious projects necessitate careful attention to the judicial, financial and technical set-up from the outset.