Steel and concrete towers, the hum of the tram, a congested ring road... In this urban landscape of the 13th arrondissement of Paris, in the south of the capital, a warm-coloured building contrasts with the surrounding greyness.
This 50-meter building owes its color to wood, a renewable material, chosen to erect its structures and fifteen floors of apartments mainly intended for rental.
The wood construction industry is in its infancy in France, but Paris, a mineral city par excellence, aims to extend its use in order to favor the "most ecological" construction methods, despite restrictive regulations and high costs.
"We made the political choice to build green buildings in Paris, particularly since 2020," recalls Jacques Baudrier, deputy (PCF) to the mayor of Paris in charge of housing and ecological transition.
The elected official supports developing "as much as possible" housing "in wooden structures and windows" or even "cut stone", to the detriment of concrete and plastic, during an interview with AFP.
"Wood, earth, straw"
Regarding the housing construction programs underway in Paris, the deputy estimates the share of wooden buildings at a range of 25 to 30%, without giving precise figures.
Still largely dominated by concrete, construction worldwide accounts for nearly 40% of CO2 emissions if we include the lifespan of buildings and their energy consumption. Cement alone generates 7% of global greenhouse gas emissions according to the GCCA, the World Cement and Concrete Association.
"In the buildings we are currently constructing, we are often below 600 kg of CO2 per square meter, whereas a standard concrete building is more like one ton of CO2 per square meter," argues Jacques Baudrier.
The RE2020 Environmental Regulation, which sets the standards for new constructions in France, requires this change to be made from January 1, 2022.
"Its objective is to banish concrete as it currently exists," notes Christophe Millet, architect and president of the National Council of the Order of Architects, for whom "we must return to the world of the children's story of the "Three Little Pigs": wood, earth, straw."
"If we want to make very ambitious ecological buildings, wood is essential today," adds Pascal Gontier, architect and professor at the Paris-Malaquais - PSL school of architecture, who built two wooden buildings and "four in mixed wood-concrete" for the Paris Olympic Games.
Persistent brakes
But building with wood involves overcoming many challenges.
Indeed, "French wood is expensive," qualifies the researcher at the National School of Bridges and Roads Arthur Lebée. It is not very abundant in the absence of a developed sector, despite the increase in the area of forests.
In the 2.700th arrondissement of the capital, the Wood Up tower cost "around 2 euros per m2.300" compared to "XNUMX" for a standard building in Paris, estimates its developer Paul Jarquin (REI Habitat).
For this project, French wood was transported by river, on the Seine. But "a good part of the works are often made from imported wood", points out Arthur Lebée.
In Paris, wooden construction is also subject to strict regulations on fire risks, supervised by the Paris fire brigade.
While "precautions must be taken", wood is "a safe material, it burns at a very precise speed that can be perfectly defined, unlike other much more unpredictable materials", says architect Pascal Gontier.
Faced with more stringent standards than in other European countries, the Order of Architects is calling for a "change in regulations" as well as an "acceleration of technical opinions", while Paris wants to make the capital "the Mecca of green construction in France".
