Complemen’terre: Reviving Local Know-How

Led by the Built Heritage mission of the Parc Naturel Régional des Caps et Marais d’Opale, the Complemen’terre training program follows a clear ambition: to preserve traditional know-how related to local heritage, with techniques such as cob and raw earth plasters.

With the support of the Fondation du Patrimoine, the association Maisons Paysannes de France and its local branch, as well as the Bernard Chochoy Vocational High School (Lumbres), this initiative, launched two years ago, is proving promising… here’s the story!

The clay-loam soils (Quaternary) of certain areas within the Cross-Channel Geopark are perfectly suited for making cob, but one problem remains: trained professionals in this material are now rare. Complemen’terre addresses this need by providing the basic knowledge required to integrate raw earth construction techniques into existing carpentry or masonry activities… or even make it a specialty of its own.

Nothing beats practice for learning: training sites allow participants to directly apply the gestures and know-how. The goal of Complemen’terre is to train today to prepare for tomorrow… to learn solid foundations for preserving our local heritage, but also to build and design new ecological buildings!

Made possible thanks to funding from the Communauté de Communes du Pays de Lumbres, the Communauté d’Agglomération du Pays de Saint-Omer, the Fédération Française du Bâtiment (FFB), the Campus des Métiers et des Qualifications label, and with the support of the Fonds Verts under the Cross-Channel Geopark, these training sites have brought people together, allowed the transmission of ancient knowledge, and advanced local projects.

Craftspeople, vocational school teachers, and residents worked together to meet the needs of the territory, contributing to three concrete projects:

• Restoration of a nature hut in Zudausques (earth-lime plaster)

• Rehabilitation of a cob barn in Wismes

• Hemp-clay insulation of a former farm building converted into a community hall in Wimereux

Each project was designed to meet real local needs while passing on sustainable skills.

Sometimes, heritage is rebuilt… stone by stone. The Audresselles wall received the “Parc’s Favorite” award, thanks to the rarity of the practice: building new structures using old techniques and materials. After the transformation of a group of dilapidated village houses, the old stones were salvaged, sorted, and reused for a redevelopment project in the town center. This ultra-short supply chain reduces environmental impact while preserving the local character of the built environment.

This project mobilized landscaping students, supervised by a craftsperson who trained them directly on-site—truly killing two birds with one stone! Residents, social inclusion associations, and municipal employees also lent a hand, gaining skills for future projects. The work involved sandstone and limestone with lime mortars, an ancestral know-how omnipresent in old buildings, rare in today’s practices, but particularly well-suited for construction with natural materials that could well become “the heritage of tomorrow.”

The Audresselles wall is only one step in a broader, long-term mission: preserving stone heritage, building and rehabilitating with raw earth, raising awareness about local resources and know-how! With the support of the Parc Naturel Régional, local associations, and municipal initiatives, the Built Heritage mission of the Cross-Channel Geopark is carrying out these projects over the long run, in connection with the geology and history of our territory.

Geodiversity Day reminds us that the richness of a territory also lies in its rocks, its soils, and the uses that come from them. By rehabilitating with local materials and training in skills that endure over time, the Cross-Channel Geopark is working for a living heritage, respectful of the environment and full of promise for the future…

What if you, too, took part in preserving local know-how?

On October 4th, a participatory cob workshop in Alquines allowed the public to contribute to the restoration of a historic village barn—an opportunity to learn techniques and gestures alongside a skilled artisan!

To find out more about our upcoming workshops and participatory training sites, check out the Cross-Channel Geopark events calendar!