An urban development by using earth as a construction material
One of the key players of the project Earth Cycle is the urban developer as he is an end user and promotor of new technologies.

By observing the steering committee meetings of Earth Cycle, it was obvious for me that exchanging in a Zoom-in with Ludovic Boespflug is important to show the specific role that QUARTUS plays in this project. This interview took place during the Covid-19 crisis and in our dialogue, we considered the encountered difficulties related to the project organization and delay respectively.

Ludovic is Deputy Managing Director of the company QUARTUS Urban development. He leads the implementation of innovative urban projects in large French metropolises, with special involvement in Lyon, his city of residence.

Presentation of QUARTUS by Ludovic Boespflug

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Designing and realizing an urbanity that responds to new uses requires being attentive and close to the expectations of our customers, our users, the inhabitants of the cities and countryside

By these words, Ludovic Boespflug, deputy general director of QUARTUS, presented the vision of an innovative urban developer. In fact, using earth as a construction material isn’t a classic approach in this field where steel and concrete are dominant. He continued by saying: community of users, community of neighbors, community of exchanges, community of spirits – QUARTUS is convinced that the real estate of tomorrow will be mixed, open, alive, shared, and that the mission of its actors is to give back the flexibility, collective sense and attractiveness to enable everyone to succeed in their life and their city, sustainably.

This presentation focusing on innovation, allowed starting a dialogue about the role of an urban developer and real estate company to promote sustainable development. In fact, his first words were: We need a holistic approach, as we are an urban assembler. This summary prepares the continuation of the interview on the genesis of the project.

Reversing the model is the idea of QUARTUS. We start from the people, said L. Boespflug, the users, and the fine knowledge of their expectations, to personalize their space. We bring all services to the foot of their building by preferring the local components all that make the singularity of the neighborhood.

It is a careful vision of the urbanity that animates us, a certain idea of the happiness of proximity. The three key words are: INCLUSIVITY, ECOLOGY and LIFE. Improving the functioning of living beings is one of the major elements of QUARTUS policy.

For him, the city is open, connected, centered on the human aspects and sharing. The reflection on new uses occupies a central place: whether digital, ecological, creative or cooperative, these new uses are at the heart of urban developments and redesign our cities.

 In 2016 /2017, the major authorities of Paris Metropolitan area launched a call for proposals towards a new way of urban development in the Parisian area. It was called ‘Reinventing cities’ with various components: metropolitan concerns, the Seine river, the underground and also dedicated lands for urban development and regeneration. QUARTUS was involved in the submission of a project with some of the partners later involved in Earth Cycle

At the same time, an important architectural and urban exhibition took place in the Arsenal Pavilion in Paris ( The commissioners of this exhibition were the architecture studio Joly&Loiret and the Amàco association.

In parallel, the European call for projects of the Urban Innovation Actions Initiative had started its second season and the Ile de France region was encouraging the implementation of responses to this very interesting call.  The Ile de France region provided communication and assistance in setting up with local authorities in the region to encourage them to respond to the call for projects for Urban Innovation Action and subsequently, it contributed financially to the project. This conjuncture made it possible to consider the passage from the idea to the action and to the project thereafter.

Ludovic was interested by this innovation and the question of earth excavated from the Grand Paris Express Metro line ( was considered as a priority by the concerned local authorities and the French government in charge of this gigantic project.

The Mayor of Sevran was seduced by the idea of participating in an earth materials factory, as he is going to have two metro stations in his town. Negotiations between private partners and the city of Sevran took place before the submission of the project to identify the best scheme of partnership. Who is investor and who is owner of the factory? This type of partnership is new in France and allows to be applied on other actions in connection with private and public stakeholders in the service of innovation.

The virtues of the use of raw earth are numerous, in terms of hygrometry for example, playing the role of thermal stabilizer, reducing or replacing the use of air conditioners and offering the building high comfort and acoustic resistance. It is a 100% natural, recyclable material with great inertia. Mud walls act on interior temperatures by storing or de-stocking the captured energy, which improves comfort in summer and winter.

Left raw or coated, bricks produced by Earth Cycle offer a wide range of treatments. Brushed with linseed oil, they immediately return to their original appearance. If the use of BTC is slightly more expensive than traditional brick (from 150 to 210 euros per m2 depending on the level of finish, installation provided), the overall cost of conventional construction, covering the bricks included, is equivalent.

The raw earth is also 100% healthy and free of VOCs (volatile organic compounds, considered the first source of pollution of inhabited spaces).

Ludovic recalled that during this period, QUARTUS has changed CEO twice, and despite the fact that the earth activity is far from their major concerns, and the earth construction activity is not profitable yet, the support of the CEOs was flawless. The word Geo resource is now commonly used. It doesn’t have yet the same level of recognition yet as Bio resource but it is just the beginning! It is not only thanks to the promoter but to a whole team which believes in this resource.

Here is a beautiful earth wall
Source (
The Earth Cycle factory in Sevran (source: Earth Cycle Site)
The aspect of one of the first wall produced by Earth Cycle factory


This reflection examines the role of urban developers and other built environment actors in implementing the principles of the circular economy, as well as looking at strategies for doing so. The role of Quartus in Earth Cycle prompted me to lead this reflection.

At its simplest, the circular economy is about eliminating waste in the long-term, not just the short. The idea is to improve on the advances made by the recycling economy, which has aimed to maximize the re-use of materials before finally disposing of them, so that there is no disposal at all, just continuous re-use. It is exactly the same long-term approach and reasoning for an urban developer investing in an innovation. The long-term strategy is a term coming very often in the discussion with Ludovic. Quartus role in the Earth Cycle project is a dialogue facilitator between the private partners and the other stakeholders. Quartus is also sometimes the all-risk insurance for the project. For the cooperative company creation, the initiator was Quartus as they consider the proposed business model as the most sustainable from economic and environmental point of view.

The great challenge of future urban development is to transform our disposable society into a circular economy where as little as possible is wasted and recycling is permanent process. As the property development sector has historically been a major contributor to global CO2 emissions, the principles of the circular economy must be at the heart of the future direction of the industry, including in the way we plan our urban spaces. Regarding this environmental concern, Quartus team participates actively in the writing of the ToRs (Terms of reference) regarding environmental assessment. They played the game of the prescriber who allowed Cycle Terre researchers and scientists to enhance the environmental side through the concepts of LCA (Life Cycle Analysis) and metabolism. These elements will be showcased in the showroom that will be offered in the Quartus premises in Paris.

Concerning the Marketing section, Quartus is also a very important player in Cycle Terre. Sevran and the factory are a little out of the way of the decision-makers, architects and specifiers, who are in Paris. Quartus will set up a show room to promote the factory and the entire earthen construction process. This component is very important for the sustainability of the project at the end of the UIA implementation period. This integrated approach is common to the Quartus philosophy and Earth Cycle spirit. Envisaging how our urban designs can be made truly circular, we need to take account of social and economic sustainability, as well as the environment. For Ludovic, this long-term integration is one of the major successes of Earth Cycle. This broader concept of sustainability has guided Earth Cycle project in the development of its vision for responsible design, considering not just the environmental impact, but also the human and social impact. Job creation and local economic development are also a major achievement of the UIA project.

Now, in every project that Quartus creates, they start by considering the environment within which the buildings or the projects will sit. Every development has a unique hinterland and, if it is to be part of the circular economy. The understanding of the wider context and the ways in which the development will interact with it in the future is one of the major theoretical achievements of this relationship of intellectual complicity between Quartus and Earth Cycle.

The cost of the factory building, the competiveness of the final product and the technical performances have always been challenges for Earth Cycle. These are important issues and the complicity between the different partners made it possible to overcome the obstacles. 

For example, the BTC (compressed earth brick) was preferred to extruded earth, as more data on the material are available. Other technical concerns were continually discussed. The contribution of architects, researchers and earth specialists allowed to optimize the process and to demonstrate from economical point of view, the environmental added value of earth as a construction material. 

The message is well established and now shared beyond the consortium and several projects have emerged. This compromise and dialogue in Earth Cycle is one of the strongest points of the project. It isn’t any more a consortium; it is now a team that shares values, principles and above all a common reflection. The risk is also one of the major topics in the discussion as the final cost has to integrate the various uncertainties.

For example, the change of the earth supplier, the transition from Société du Grand Paris (SGP) to the group ECT ( was not planned but it turned out to be interesting and will allow a better economic valuation. This outsourcing is now an asset. This major change was crucial and QUARTUS, as other partners, had to be flexible and patient. 

Now the economic model is stable and the market is accepting this new material. This will cushion the cost and make the process sustainable. This first step relied heavily on UIA grants.

This circular economy product is a realistic achievement and also an important symbol. In fact, circular economy for QUARTUS isn’t only a flow of materials towards an optimized metabolism; it is also a social achievement. The symbolic value is important for an urban developer. As mentioned earlier, this integrated vision of the future is common between the future development of Quartus and the Earth Cycle philosophy. It is not a question of economy, environment or social concerns. It combines the three aspects with an integrated vision based on reliable and efficient governance. The cooperative created company will guarantee this sustainability.


From my point of view as UIA Expert, the role of an urban developer is important in urban innovation. The urban developer is a key stakeholder and can play a conciliator role to achieve a useful approach coming from the world of material research, ecologic convictions of an architect and a will to improve the attractiveness and local economic development of a city. 

QUARTUS and the personal convictions of Ludovic were for me an important advantage for the project success. Continuing to invest in the Earth Cycle factory is also a guarantee of perpetuity. In my perception, QUARTUS is an important element of the project success because they consider the city has to be open, connected, centered on the human aspects and sharing. This experience can be transposed to other projects.

The reflection on new uses occupies a central place: whether digital, ecological, creative or cooperative, these new uses are at the heart of urban developments and redesign our cities.

Finally, this innovative experience will allow the real estate development business to evolve to better respond to the challenges of urban sustainable development.

  • Engineer graduated from an interdisciplinary school in Toulouse, dedicated to Civil Engineering and Urbanism.
  • With QUARTUS he is the delegate dealing with urban projects, development, calls for innovative projects, dissemination of the Quartus DNA in mixed projects: uses, services, circular economy, resilience and innovation...
  • Managing a team of transversal project managers (development, assembly, innovation, uses).
  • Coordinator of various QUARTUS professions in complex urban projects (residential, tertiary, activity, logistics, senior, co-living and co-working) throughout the French territory.
  • He is in charge of Relations with Architects, selection of project partners and he is also Vice-president of the Maison de l'Architecture en Ile-de-France.

About this resource

DIAB Youssef, UIA expert
Sevran, France Small and medium-sized cities (50k > 250k)
About UIA
Urban Innovative Actions

The Urban Innovative Actions (UIA) is a European Union initiative that provided funding to urban areas across Europe to test new and unproven solutions to urban challenges. The initiative had a total ERDF budget of €372 million for 2014-2020.

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