A former military fortress in Issy-les-Moulineaux, just outside Paris, has been transformed into an eco-neighbourhood. The challenge was met by Bouygues Bâtiment Ile-de-France, which constructed 1,211 apartments (all with the BBC - Effinergie^® low-energy label), a day-care centre for children and 1,590 m² of shops, all designed with the focus on comfort for residents. On the technological side, a cutting-edge building management system will enable residents to track their energy consumption and control a range of apartment functions from a touch screen or smartphone. This environmentally responsible neighbourhood makes use of renewable energies and it is linked up to Issy Grid^®, the first project for a smart energy network on the scale of a neighbourhood.