They live and work in an abandoned convent. This is perhaps the secret of the innovative model of frugal heritage management which is emerging in Roubaix (North). After five years of conclusive tests, the collective of architects Zerm persists and signs by launching phase 2 of “Zero Seasons”. A project to break out of the shackles of thought and operation in terms of heritage rehabilitation in France.
This stage marks the start of more significant work drawing on the experience acquired through the transitional activities active since 2019 within the 6,500 m² SP building, empty since the departure of the sisters of the order of the Poor Clares in 2008. It is a question of continuing to explore the middle path of heritage preservation at a lower cost, economical and ecological. The City of Roubaix, which has few resources and many buildings to rehabilitate, initiated this approach by signing an agreement with Zerm which strips away the usual ways of proceeding and opens the site to experimentation.
Despite the rustic nature of the place, 27 structures with mixed activities have been set up there. Rental of rooms, meeting rooms and offices, exhibitions with recycled materials, activities with the neighborhood, courses for architects, film shooting… all in unheated or almost unheated spaces. In six years, the collective managed to use 75% of the surface area of this thermal strainer.
For example, it welcomed 9,000 people between January and September 2023, although the monastery is not an establishment open to the public (ERP).
Activities and frugality. “We are inventing a way to preserve the City’s heritage and finances. Between 2008 and 2018, the municipality invested around 50,000 euros per year to prevent the building from deteriorating too much and nothing happened there. Today, it spends the same amount for minimum maintenance (roofs, electrical cabinets, etc.) but the former convent hosts many activities. It’s a real collaboration,” summarizes Simon Givelet, architect of Zerm. The collective, which runs the premises and manages them with around 3.5 full-time equivalents, is paid thanks to the activities deployed via Saisons Zéro. And despite the numerous transitional uses deployed, Zerm will only have consumed 24 kWh.m2 per year thanks to its frugal approach.
To resolve the administrative constraints of developments in a place listed as a historic monument, the team benefits from support from the City but also from discussions with the Drac and the firefighters. “With the Drac, we invented the heritage mandate. We submit our small jobs to them. They respond quickly. This allows us to move forward together without having to file a building permit. Students from the Chaillot school also come to train here,” summarizes Simon Givelet.
Get to the point. This experience made it possible to identify the “frugal” work of phase 2 to be carried out as a priority. “For a traditional rehabilitation, it would be necessary to invest €20 to €25 million including tax. Here, we are going to the essential with only €10 million,” highlights the architect. A large part of the financing will come from the green fund but also from the regional council and Anru, the building being located in the heart of Epeule, a district undergoing urban renovation.
Some €2.6 million has been earmarked for the preservation of the building with interventions on the enclosure and roof which could start in the second half of 2025. Paw Architectes will ensure project management. An investment of €2.4 million will aim to recover 25% of areas that are currently unusable, such as the old wafer factory. Finally, the rest of the envelope will be devoted to bringing the building into compliance. “We will respect the ERP level and/or the Labor Code depending on the areas identified. We will thus be able to increase the number of rooms for rent, currently limited to 15,” illustrates the architect. Very satisfied with the partnership, Alexandre Garcin, deputy mayor of Roubaix in charge of the ecological and energy transition, concludes: “Investing to rehabilitate unusual heritage rather than in work affecting the daily lives of residents, such as schools, is hard to justify . It is easier, as here, to devote resources to a building that already has uses that benefit them. »
Zero Seasons, a varied program
Saisons Zéro is a unique heritage conservation project in France which combines transitional activities and cutting-edge experiments. Between 2019 and 2024, several uses were tested (with very little heating).
-Most of them have integrated the final programming of the place:
– an inn with 15 rooms (four-poster beds) open all year round;
– workshop-offices, welcoming 22 structures (associations, collectives, artists, companies, etc.);
– public programming with exhibitions, visits, workshops, concerts or residencies.
Low-tech that keeps you warm
Inner tent, hot water bottles, enclosed beds, window protection, insulating fabric on false ceiling, heated desk pads… The Zerm collective is exploring numerous low-tech solutions to keep warm while spending as little energy as possible. In particular, it uses techniques to heat people and not spaces.
It relies, for example, on convective modes diffusing heat into the rooms only when changing clothes. With phase 2 of the work, the full-scale laboratory dimension will be reinforced with the support of the CNRS as part of a European low-tech program. “We will host two theses.
The first, which is starting, will allow us to use the experiences and the second to establish our reflections on a sociological level. The prototypes created will become demonstrators,” says architect Simon Givelet.
