On 26 November 2024, the fourth regional platform meeting for bio-based construction stakeholders organised as part of the European SCALE-UP project was held in Brittany. This day, co-organised by AC3A and its member Chambers (Normandy, Brittany, Pays de la Loire and Nouvelle Aquitaine), the Fédération bretonne des filières biosourcées [FB]² and Terres de sources, brought together 34 participants to discuss the challenges of developing hemp and straw for construction. These participants, from the three regions (Normandy, Brittany and Pays de la Loire), represented the entire sector: producers, processors, craftsmen, organisations and project owners. The aim of the day was to present concrete examples of the development of hemp and straw for the construction industry, to present innovative projects and to discuss the obstacles and drivers of the development of these sectors with the sector’s stakeholders.

The day began on the farm, where Michel Kervarec, a farmer specialising in organic crops and livestock and an active member of the Terres de Sources network, presented the hemp crop that he has integrated into the rotation of his plots. The Eau du Bassin Rennais organisation opened the discussions by emphasising the importance of preserving water quality and presenting the objectives of the Terres de Sources label. This initiative supports the development of new local sectors and assists farmers in the implementation of agro-ecological practices, while guaranteeing a market and fair income for the producers involved. This year, Terres de Sources has been trialling hemp cultivation with the aim of developing a hemp industry in Brittany. The trial began with the planting of 20 hectares, thanks to the involvement of five farmers and technical support provided in partnership with the Brittany Chamber of Agriculture.

The second field visit was to the premises of LB Eco Habitat, a company created in 2011 and specialising in heritage restoration and eco-construction with bio-based and geo-sourced materials, such as hempcrete and lime/hemp or earth/lime-based coatings. LB Eco Habitat, a partner of Terres de Sources, actively promotes hemp cultivation among member farmers. Hempcrete offers interesting performance in terms of thermal and acoustic insulation, providing comfort in summer and regulating humidity in the home.

In the afternoon, the presentations continued indoors, where the [FB]² network presented the Breton bio-based sectors, its call for expressions of interest (CEI) intended to provide free support for public renovation projects using bio-based materials and raw earth, and its toolbox of bio-based materials for building stakeholders wishing to engage in eco-responsible projects. The Collectif Paille Armoricain (CPA) presented the straw sector, and the company COPANO demonstrated the properties of its straw panels designed to meet the needs of building construction and thermal renovation.

AC3A presented the biomass study (available here) carried out as part of the SCALE-UP project, and the day ended with discussions with the participants. The very positive assessment of the day showed that biomass resources and processing are ready to develop both for straw and hemp, with the support of local authorities or initiatives such as Terres de Sources. The need for cooperation between actors (from upstream to downstream) was also emphasised with a view to maintaining a strong animation of the bio-based sectors and consolidating this growing market. The objective is to have sufficient weight to encourage the public authorities to facilitate the development of the use of these materials. Finally, the day emphasised that the opportunities for farmers who engage in these sectors must be secured, and that public and private procurement is the way to achieve this.

Further information :

Terres de Sources

Fédération bretonne des filières biosourcées – FB²

Construction paille : réseau du territoire de l’Armorique

LB Eco Habitat

COPANO