โWith this approach, we strongly promote the link and circularity of productsโ
With its dual environmental approach to buildings and the built environment, Le Sommer Environnement, member of Cap Digital, promotes a more sustainable approach of construction. Since the beginning of 2000s, the environmental and engineering design office, based in Paris with a branch in Bordeaux, is strength of proposal for urban scale projects and smaller scale real estate projects including multiple circular solutions. Le Sommer Environnement is also looking to be constantly at the forefront of new trends, notably by doing a strong follow-up of R&D approaches and participating in a number of innovative projects. To understand how the office has built its expertise around eco-design and the circular economy, we interviewed Mathilde Besson, in charge of innovation management, specialized in water management and, with Jean-Christophe Aguas โ R&D director, monitors all circular economy issues at the building level.
1/ What place has the circular economy in Le Sommer Environnement projects and positioning?
The circular economy is really one of the parts that we are trying to implement in all our projects. It is notably one of the pillars of the High Environmental Quality (HQE) approach that we are going to push, depending on the projects and what is feasible. In particular, we are encouraging the use of wood construction to enable us to set up chains more easily than with other constructions. With wood it is possible to set up a chain for reuse at the end of life, we can think about modularity and dismantling upstream of the project. From the outset, we try to imagine solutions that could be reused in a number of products at the end of the construction. We also work with bio-sourced and geo-sourced materials to promote the circular economy on a local scale. This includes the promotion of working with all types of mud-brick materials like unbaked clay, terra-cotta, adobe (e.g. construction of a wine storehouse in Bordeaux) to promote local sectors and avoid construction with materials with a great environmental impact. We are also promoting bio-sourced insulation materials.
Le Sommer Environnement also conducts a major reflection on the logic of urban mining and the idea of making the city a reserve of materials for future projects. Some practical problems arise when you want to reuse, like traceability of materials, assurance that these materials can be reused or material circularity, and we are looking to overthrow them. We are helped by some technologies, in their early stages, that can encourage the reuse of materials, particularly like all BIM (Building Information Modelling) software. These information systems can put a bunch of data in a single model for the construction but also during the life of the building, gathering all the characteristics of materials, and allowing traceability throughout the project.
2/ In your opinion, how will current work on eco-design and the circular economy concretely change the face of cities by 2050?
The first stage should be acculturation, in the sense that all the themes we mentioned earlier are quite complex, require transversal approach and were not, until recently, very promising subjects. This process of understanding and absorption is starting to be well done by the stakeholders. Though, there are still obstacles to the implementation of some technical aspects and many questions to answer. How do we reuse materials? How can we be sure of their quality? How do we make them certifiable from a standard point of view but also with regard to environmental certifications? etc. Project leaders are always motivated to improve their existing projects, but they have to make a choice in relation to the constraints of the project, particularly for cost reasons, as these are trade-offs between different themes, which means that all the themes of circular economy are very rarely dealt together.
We also have to better know all aspects of the circular economy related to water. Le Sommer Environnement is thinking about closing the water cycle and in particular the wastewater cycle. We are promoting the idea of recovering at source, at the foot of buildings, raw materials and resources contained in wastewater (nutrients for crop fertilization, organic matter for agriculture and energy production, water as such for reuse within the city) to create internal links and loops within the city but also links with rural and agricultural areas where there is a strong need for nutrients. On the grey water reuse, we are working directly with companies, offering more or less ready-made solutions thanks to market development. On the urine recovery and recycling, it is still an innovative subject, so few companies offer turnkey solutions and we are on the borderline between demonstration, applied research and classic projects. On the recovery of black water (water from toilets), there is little work in France even so it is quite developed in the countries of Northern Europe. We are more on exploratory approaches with research subjects closer to the academic world (Design project co-financed by the French national research agency ANR).
The last subject related to the circular economy and eco-design is the recovery of bio-waste, organic waste from housing and food processing equipment. Soon there will be an obligation for all producers (individual and industrial) to collect this waste. Both questions in research for technical solutions for bio-waste recovery and there is a link with companies looking for solutions to implement (MEIKO).
3/ What do you think the face of cities will be in 2050?
Ideally, cities should no longer operate in a linear way. We would no longer come to see the city as a consumer of resources of any kind, but would come to look at the different flows included and try to loop them. For the construction industry, it means thinking about the end of life of the buildings we are building and we are going to design. But for older ones, we need to think about the waste produced during their deconstruction and reuse and there is no preconceived toolbox for it.
The question of flows is also important: recovery of fatal energies, data centres, waste water, etc. The idea is to integrate the different components of the city so that they can be looked as a global system, and no longer think of putting aside construction, energy, waste and water management. All these aspects should be studied together, I hope that this will be the city of tomorrow.
By the way, the place of digital technology in this city is crucial in order to make all these loops work, since some of them are one-off (reuse at the end of their life cycle, keeping traceability), others more frequent (questioning about the life cycle, recovery of fatal energy that works hour by hour and questions the dynamic aspects to be considered). Digital (sensors, data, and loops) is developing more and more and will continue to do so.
4/ You refer to many bricks of solutions for environmental design. How do you evaluate their acceptance by the actors of the sector as well as by the citizens?
For the users/citizens, we have a few direct feedbacks, since we work mostly during the conception of the project and not during its life. But by the actors of the sector we have some feedbacks, since the bricks are proposed to the different project leaders. As time goes by, we know that some solutions will have a stronger acceptability than others. Technical solutions are increasingly being implemented, and all the players in the sector are more and more familiar with them. For instance, we were able to have feedback on natural ventilation, an old practice but re-implemented nowadays, it worked very well where it was introduced. It is necessary to communicate the expectations and the levels of performance that we want to achieve since it depends mainly on the outside temperature (e.g. be careful during very hot periods). We try to implement it in office buildings or high schools but also hotels in order to reduce the energy consumption for air conditioning.
