In 2020, France’s carbon footprint is estimated at 552 Mt CO2 eq, which means 8.2 t CO2eq per person. Half of these emissions are due to local activities, especially at district scale. Thus, the built area are key systems to reach the goal set at 2t CO2eq per person in 2050. To meet this goal, improvement of the knowledge on the environmental performances of build area is necessary. The aim of this paper is to share the results of a national environmental assessment performance campaign, carried out in France from 2020 on thirty districts. The performance is measured based on the Life Cycle Assessment (LCA) approach. Supported by ADEME, a joint LCA method for district environmental assessment has been published in 2021. It’s implementation in an assessment software (i.e. UrbanPrint) allowed to quicky deploy it. The input data necessary for the assessment are the master plan and the main characteristics of the project. Different scenarios can be compared with a reference or a “business as usual” one. The analysis allows to obtain quantified results, to identify the main hotspots and each activated lever effect. A Shapley analysis proposes new levers to reach the best environmental performances specific for each district.