in Brest, the HLM office is building cardboard houses

While some private owners have already opted for cardboard construction, for the first time in France, the city’s HLM office has had six houses built entirely out of cardboard.

This is a first in France: the HLM office in Brest, in Finistère, is building six cardboard houses, presented as more ecological than traditional structures. Delivery is scheduled for April. Franceinfo went to visit the construction site of these houses unlike any other.

In the Breton rain, workers embed large panels into the wooden frame of the house: “It’s really cardboard!” A source of pride for Cédric Rocher, who supervises the site: “It’s a succession of layers of cardboard and there is a protective membrane which makes the cardboard waterproof. We choose the thickness of the cardboard according to the insulation we want. My colleague couples blocks of cardboard to be able to insert them into the ground to insulate the floor. Also, the floor is entirely insulated in cardboard”he describes.

“72% CO2 savings”

Like the walls and the roof, here, it is a zero concrete construction, even for the foundations. “We are placed on metal piles which are screwed into the ground. Under the houses, it is only earth”, Cédric Rocher would like to clarify.

Which in no way weakens the structure: the site even withstood storm Ciaran which blew through Brittany in October-November 2023: “In the park, a little further on, all the trees have fallen down. The facade of the building faces west and it hasn’t moved. The way the cardboard cells are made creates rigidity.” And strong insulation – much better than classic glass wool – all with a significantly reduced carbon footprint.

Alain Marboeuf, boss of Bat’Ipac, based in Nantes, is the creator of these cardboard panels: “We have products that come entirely from the recycling of cardboard paper. Once we have produced this sheet of paper, we will make corrugated cardboard from it. The corrugations are glued to each other with wheat starch . So we are dealing with a rather clean and healthy product!”

“If we made a comparison today with what we call conventional construction, we have 72% CO2 savings.”

Alain Marboeuf

at franceinfo

The HLM office has ordered six houses so far. Cardboard is being tested, explains its director George Bellour: “We will wait to see how it behaves over time. There has been a first experience for ten years in Belle-Ile-en-mer, and there has been no disaster or particular problem. Obviously, If it’s conclusive, there’s no reason why we shouldn’t reproduce it.” An initiative that is all the more attractive given the cost of these constructions: 2,000 euros per square meter. Today it is comparable to traditional construction sites, which have become more expensive since the explosion in the price of concrete or steel.