The paper concerns the definition of guidelines in the design of a new urban settlement, based on system energy utilization and building environmental impacts and sustainability improvement. The study refers to a 160000 m2 area sited on the outskirts of Carmagnola, a city close to Torino, where the municipality decided to locate about 1260000 m3 of commercial buildings: offices, shopping centres, a trade fair area, a cattle market, a multi-hall cinema, hotels, restaurants, industrial sheds.