A first in positive and low-carbon renovation, the new Montparnasse Tower,, will have reduced its energy consumption by 10 times compared to the original project. In the similar way as a Glider aircraft, it will be autonomous for 70% of its operating time, during which it will not use any active systems. A very ‘Parisian’ tower; ultra-contextual and symbiotic, its integration within the district will be based on improving urban air comfort and on the logic of the mutual benefits of energy complementarity.