Case Study: Environmental Feasibility for Paris' Charles de Gaulle Airport Expansion

Background & Context

Terminal 4 (T4) was a major expansion plan for Paris Charles de Gaulle Airport, proposed by Groupe ADP to handle an additional 35 to 40 million passengers annually and solidify the airport’s status as a leading European hub. Estimated to cost between €7 and €9 billion, the project included new runways, passenger terminals, and supporting infrastructure. T4 was envisioned to accommodate growing air traffic, enhance passenger services, and boost France’s connectivity in the global aviation market, with construction initially planned to begin in the early 2020s.

The proposed expansion would have generated over 10 million tons of excavated materials. Drawing from our experience with large infrastructure projects in Paris, such as the Grand Paris Express, we carried out a feasibility study to explore potential valorization solutions for the excavated material, with the goal of exceeding regional and European objectives for major infrastructure projects.

What We Did

• We identified the potential for material recovery from the project's excavations, including all technical and economic considerations

• We drafted a series of recommendations for the French Environmental Agency on the management of such excavated material

• We proposed how to integrate the site into the Ile-de-France recycling ecosystem, including the the potential for an on-site recycling platform, synergies with external local recyclers, and technical and operational management in line with airport constraints.

Outcomes

The airport expansion ultimately did not move forward, because the project came under intense scrutiny for its significant environmental impact and carbon emissions, seen as incompatible with France’s climate objectives under the Paris Agreement. Critics warned that expanding airport capacity would encourage more flights and higher greenhouse gas emissions at a time when France has been aiming to drastically reduce its carbon footprint.

As a resut, In early 2021, the French government decided to cancel T4, citing the need for infrastructure projects that align with sustainability and ecological transition, marking a clear policy shift away from large-scale airport growth toward greener alternatives.

However, as transportation itself becomes more sustainable, we believe the project may be revisited at a later date, and our feasibility study regarding the circular treatment of the project's excavations will remain valid.

Clients & Partners