FAVORITE - Linen, a Natural Insulator in Support of Decarbonization

Linen, a Natural Insulator in Support of Decarbonization

Portrait of an engaged and innovative agricultural flax cooperative: L.A Linière. Specializing in flax cultivation, L.A Linière brings together passionate and dedicated flax farmers. Focused on the future, it combines ancestral know-how with sustainable innovation. We spoke with Maxime Stievenard, head of business development at Bâtilin, a subsidiary of L.A Linière, about his vision for flax cultivation.

In 2019, L.A Linière met with Constructions-3D. In search of local bio-based materials to build its structures, particularly the very first one in 2019: The Pavilion, Constructions-3D naturally turned to the cooperative for flax shives. The goal was to develop more sustainable and eco-friendly construction methods by using local, renewable natural resources like flax. A true technological breakthrough, this project has become a reference in building construction with alternative, local, and carbon-negative materials.

Today, the flax cooperative has expanded its activities and entered the construction market. We spoke again with Maxime Stievenard, head of business development at Bâtilin, a subsidiary of L.A Linière, about his vision for flax cultivation and its future.

A COMMITTED FLAX COOPERATIVE

FLAX HAS A LOT TO OFFER

Flax is the first textile material developed by humans. It’s an ancient crop that symbolized purity in its time. Flax has persisted through the centuries until today. It is a plant fiber cultivated along a wide coastal strip from Caen (Normandy) to Amsterdam in the Netherlands, also including Belgium. The quality of flax relies on unique geo-climatic conditions and craftsmanship, making its production non-relocatable. Three-quarters of the world’s flax production is grown in Western Europe, with France as the global leader.

BATILIN : A RESPONSIBLE INITIATIVE

Bâtilin offers a bio-based insulating block made from flax concrete for building insulation. Made from flax shives, a by-product of flax scutching, B TILIN blocks provide true comfort for occupants through the beneficial properties of flax. Thanks to its insulating properties and high thermal inertia, the B TILIN block helps keep interiors warm in winter and cool in summer. The walls breathe! It can regulate humidity levels and offer greater comfort. Its composition also improves acoustic comfort in buildings. By significantly reducing energy consumption, it contributes to substantial savings on heating and air conditioning bills. Carbon negative, Bâtilin blocks are made from flax shives, a 100% French natural and local resource. They also offer a 3-hour fire resistance (20 cm block). It’s a bio-based material made from a natural and local resource.

We were looking for a way to better use flax shives, a by-product that had previously been underutilized. The shive is the woody part of the plant found inside the flax stem. During scutching, the fibers are separated from the flax stems, and the central stem is broken into small pieces called shives. Composed mainly of lignin, shives have properties similar to wood chips. They represent 50% of the plant’s mass. Each year, the cooperative collects 15,000 tons of shives, enough to build between 300,000 and 500,000 square meters of housing. Before Bâtilin, flax shives were mainly used for animal bedding. In Hauts-de-France, they were used in attic insulation, and the new use of biomass in the building sector led us to create an easy-to-install, carbon-negative block.

Mixed with lime and water, the flax shives, previously used in horse bedding, become concrete with interesting technical characteristics for construction.

In construction, the applications are numerous: it can be used as infill combined with post-and-beam structures (wood, steel, or concrete) and as insulation for interior, exterior walls, slabs, and partitions.

We control the raw material. It’s bio-sourced, local, 100% French, and classified as a waste product. The main idea was to create an easy-to-install block with good thermal inertia and a carbon footprint that aligns with current and future challenges.

3D PRINTED CONCRETE: AN OPPORTUNITY FOR THE FLAX INDUSTRY

At this stage, our block isn't load-bearing, but who knows? With a real R&D phase, 3D printing of flax concrete could quickly become a reality.

A PROMISING FUTURE

We are developing several accessories, finalizing our technical evaluation, and planning to open our new factory in 2026-2027. In the long term, other products may emerge, but our goal is to scale up the production of our block, which fully meets decarbonization needs. Social housing projects, schools, sports halls, and theaters are in the works, as well as numerous projects for private individuals.