“Eco-material”, a common term since the 1990s, entered the French dictionary in 2019, where it is defined as a “construction material whose use respects the environment”. It includes stone and raw earth (geosourced, mineral-based materials), as well as wood, straw, hemp and reeds (biosourced materials that come from plants or animals). For the construction industry, which is responsible for one third of domestic greenhouse gas emissions, according to a June 2019 study by ADEME and Carbone 4, these natural materials are a major source of interest. Extracting, harvesting or sawing these materials requires relatively little energy, and they can be recycled, reused and processed with a lower environmental impact than other materials. 

“At the same time, a government label will allow public or private contracting authorities to anticipate the future requirements of RE 2020, set an example, and serve as a prelude to future buildings farther down the line.” These measures will trigger a radical shift in building types and construction methods, “which will require site workers and tradesmen to alter their practices and undergo training. This is particularly true when it comes to using wood and biosourced materials, which will substantially change how construction sites are designed, supplied and managed.”

These threats include climate disruption, an excess number of large game animals (which impede forest replenishment), and unfavourable opinions toward hunting and logging. This restructuring of the forest-timber industry, which is running a deficit due to log exports (particularly to China) and imports of processed products such as CLT, is vital. 

The foundations for tomorrow’s buildings have already been laid. Often compared to the homes of the three little pigs, a number of straw, wood and brick buildings from major construction companies and fledgling developers, like REI Habitat and Woodeum, are making headlines. Having earned E+C- labels (for positive-energy and carbon-reduction buildings), these innovative structures, inspired by the past, helped push through the 2020 Environmental Regulation bill, even before they were subject to its rules. They have “set an example and serve as a prelude to future buildings farther down the line”, to borrow the words of Emmanuelle Wargon, Minister Delegate for Housing to the Ministry for the Ecological Transition—and for good reason. 

The public delights in reading about the origin of the ashlar used in the Le Metropolitan project (a group of 283 homes under development by Verrecchia Construction in Rosny-sous-Bois, Seine-Saint-Denis): the Saint-Maximin quarry in the Île-de-France region. 
They enjoy learning that in order to complete a project in Confluence, Lyon (a 1,000 m2, three-story building designed for Ogic by architecture firms Clément Vergély and Diener & Diener, which was made with rammed clay—a traditional technique from the Rhône-Alpes region), Nicolas Meunier’s team used earth from an excavation site less than 20 km away. 

The builders have pledged to use traceable materials, as in the restaurant industry. “For each stud, each floorboard, we can tell you who the manufacturer is, and which massif it comes from”, promised Paul Jarquin, Chairman and CEO of REI Habitat, during his presentation on L’Hester, a property-development project that delivered a twenty-unit, “locally sourced” apartment building in early 2020. The builders also pledged to indicate which forests the wood (primarily spruce) came from: the Grand-Ouest region, Massif Central, Jura or the Savoie Massif. Working with local materials whenever possible, and with local partners, is also the goal of Bouygues Bâtiment France Europe.

In the countryside, Jean-François Daures’ green school complex in Montpezat-sous-Bauzon, near Aubenas, which was delivered in 2014 and won the Sustainable Construction Grand Prize at the Green Solution Awards in 2019, is in perfect harmony with the surrounding scenery. Vegetation is everywhere: in the Douglas-fir superstructures, sourced from the Cévennes region, as well as the roofing, the cladding and the scenery. Even the road that runs by the school has been decorated with greenery. The idea, according to the architect, was to “pull the prairie green over the school complex, covering it in a plant canopy”, and to showcase local biodiversity. The teachers have all noticed a marked improvement in their student’s well-being, as well as an increase in academic performance. In Aerem’s straw and wood factory in southern France, delivered in 2018 by the Toulouse-based firm Seuil Architecture, the workers say it’s easy to forget about the winter and poor weather, which are more noticeable in concrete buildings.

However, in Canada, studies show that cancer patients recover more quickly in such an environment.


Feats of architecture and urban planning 

Using eco-materials doesn’t rule out bold architectural styles. Wood, which is five times lighter than concrete, allows for construction in the French capital, which is already highly dense, as well as in underground car parks—as was the case with the Saint Mandé apartment complex. The material is also being used by Woodeum to build a three-building residence hall for students and young athletes over the Paris ring road at Porte Brancion, and was also used to add five floors to a supermarket at Place de la Nation.

The growing appeal of new techniques since the end of the 19th century—including concrete and steel—as well as the wartime loss of manpower and expertise passed down from prior generations, have weakened the wood, straw and stone industries since the 1960s. However, these industries are still in the picture, and the new environmental regulation (RE 2020), which is designed to reduce buildings’ carbon footprints by encouraging the use of biosourced materials, should pick up their burgeoning momentum once it is implemented in summer 2021. 

Stone, for its part, still boasts 715 specialised companies and 4,000 direct jobs, with revenues of 515 million euros, according to figures from the natural stone industry. Lastly, raw earth, which is promoted by the CRAterre  association, will be the subject of a “national project” currently under development by the Ministry for the Ecological Transition. The forest-timber industry carries the most weight. According to the April 2020 report from the Court of Auditors (Developing the Forest-Timber Industry, Its Economic and Environmental Performance), the sector accounts for 440,000 jobs (compared to 1,200,000 in Germany) and 60 billion euros: 20 billion upstream (logging) and 40 billion downstream (the wood processing industry, including real estate developers, sawmills, carpenters, joiners, energy engineers, papermakers, etc.) 

However, only half of its annual growth is harvested, and it is poorly integrated between the upstream and downstream ends of the industry, between supply and demand: it exports less rough timber than it imports processed products, leading to a substantial, seven-million-euro trade deficit, which widened by 4% between 2018 and 2019, according to an August 2019 report by Agreste Infos Rapides (Wood and Wood By-Products). With a forest area 45% smaller than that of France, Germany’s lumber production is almost three times higher (23 billion m3 vs France’s 8 billion m3); Austria also exceeds France, with 9.6 billion m3 of lumber. 

As noted by Fabrice Denis, VP Strategy, Wood Construction at Bouygues Bâtiment France Europe, “while forests are suffering the consequences of climate change, they also offer a response to it. (...) Lumber can help reduce emissions by 10%; and growing demand downstream will pull the supply side along with it.” 
The upcoming environmental regulation (RE 2020), the 200-million-euro relief package announced by Julien Denormandie on 22 December 2020 (which was developed to protect forest resources and plant 50 million trees), and the 70-million-euro Wood Fund created by BPI France, should allow the industry re-organise itself more smoothly.

Joint interview with FABRICE DENIS, VP Strategy, Wood Construction at Bouygues Bâtiment France Europe, and MARC FRANCO, Director of Coldefy Paris and the architect in charge of Novaxia’s Wonder Building project, which is being built by Bouygues Bâtiment Île-de-France – Construction Privée.


How does Bouygues Bâtiment France Europe, a concrete builder, intend to become a leader in wood construction in ten years? Especially since “building with wood doesn’t mean you’re replacing concrete with wood”, as noted by Fabrice Denis, VP Strategy, Wood Construction at Bouygues Bâtiment France Europe. Details below. 

Our second objective: to provide a fundamentally different experience to all stakeholders in the industry, since it’s faster, less noisy and less dusty. Five to six fewer lorries are needed to deliver the materials. And since it’s more ergonomic, it offers the possibility of welcoming more women to our sites.
Lastly, wood is great at pushing us to reconsider what we do and how we build. Building with wood doesn’t mean you’re replacing concrete with wood. 

MARC FRANCO, YOU’RE THE ARCHITECT IN CHARGE OF NOVAXIA’S WONDER BUILDING IN BAGNOLET, WHICH IS BEING BUILT BY BOUYGUES BÂTIMENT IDF AND SHOULD BE DELIVERED IN OCTOBER 2022. HOW REPRESENTATIVE OF WOOD CONSTRUCTION IS THIS PROJECT? 

M. F. – In this 27,000 m2 building, wood is practically everywhere—in the studs, beams, floors, stairs—except the façade, since wood turns grey over time, and this isn’t to everyone’s taste. On the other hand, it’ll be more noticeable indoors, as it’ll be protected by a white surface coating that leaves the wood grain visible. 

FABRICE DENIS, BOUYGUES BÂTIMENT France EUROPE HASN’T LEFT WOOD CONSTRUCTION TO A DEDICATED COMPANY. WHY?

F. D. - We ruled out that idea because it’s an issue of cultural transformation. It’s like when an automaker transitions from petrol to electric, or in Total’s case, from petrol to solar. To carry out this transformation, all of our companies and subsidiaries are learning about wood construction and its challenges. To help them, we created “WeWood Academy”, which offers structured training to all company personnel. 

MARC FRANCO, COLDEFY HAS BEEN WORKING WITH BOUYGUES CONSTRUCTION FOR A LONG TIME. WHAT ADVANTAGE DO YOU GET FROM THIS, ON YOUR END? 

MF. - Being an architect is like being an orchestra conductor: we have an overall vision of the piece, and it’s great when we get to interpret it with highly skilled specialists. We’ve been working together for twenty years, and I appreciate their expertise. These are major building professionals. They have a pretty incredible strike force, with specialised engineers. What we’re lacking in our industry is training. When they pass down knowledge, they do it in the field, between specialists and novices, between seniors and juniors. It’s a pleasure to see that on the worksites.

WHAT ARE YOUR OTHER PRIORITIES?

F. D. - Our second priority is to make sure that the wood comes from sustainably managed forests, and that all our wood is PESC- and FCS-certified. WWF is supporting Bouygues Construction towards responsible wood sourcing. The third is to focus on local supply chains and jobs, and to use wood from the region whenever possible, or French wood, even if it ends up costing us more. We’re also in the process of developing framework agreements that require a certain percentage of French wood in our buildings. Every call for tenders is an opportunity to build ecosystems, since it’s in our long-term, collective interest. 

IS THERE REALLY DEMAND FOR WOOD? 

F. D. - The demand is exponential. In 2020, it was three times higher than in 2019. The hygroscopic health benefits of wood have been proven: in a wooden hospital, people receive faster treatment, and their heart rates decrease. Wood creates a soothing environment. It also allows for amazing architectural shapes, not just high-rise buildings. Investors and users also care about the carbon footprint of construction.

BUILDING REVERSIBILITY IS A SUSTAINABLE CONSTRUCTION ISSUE. ARE WOOD BUILDINGS A BETTER CANDIDATE FOR THIS THAN CONVENTIONAL, CONCRETE BUILDINGS? 

F. D. – Future buildings will be more hybrid and flexible. Wood allows you to modify the building over time, so that it can adapt to subsequent changes in lifestyles. Construction methods such as screwing allow you to more easily reconfigure the interior space than in a concrete building, whose connections are made of reinforced concrete. This also contributes to users’ mental comfort, as it allows them to experiment with a new, more reassuring type of housing, against a sometimes-stressful backdrop of urban densification.