Construction is expected to begin in 2015 on the 3.7km extension, which will have six stations, and the project will take around three years to complete. The line will terminate at a new public transport interchange outside the RER station in Juvisy, which is served by RER Lines C and D.

The extension is expected to cost €198m including rolling stock with funding coming from the French government, Ile-de-France Transport Authority (Stif), the départment of Essonne, and the regional governments of Ile-de-France and Paris. Stif will finance the acquisition of 12 additional LRVs at a cost of €33m.

The initial 11.2km section of the line between Villejuif/Louis-Aragon and Porte de l'Essonne in Athis-Mons was inaugurated on November 16.