Could ‘augmented wood’ be the future of construction?

Wood is mankind’s oldest building material, but seldom do we use it. You certainly don’t see many tall buildings made out of wood—the superior strength and relative inexpensiveness of steel and concrete have sidelined its usefulness. 

Timothée Boitouzet, the founder and CEO of Parisian Startup Woodoo, says that to save our planet, this must change. “Wood is the only construction material that grows by itself and it is one of the only construction materials that absorbs C02 rather than emitting it,” Boitouzet says.

Construction is responsible for around 25 percent of all greenhouse gas emissions, across its supply chain, and this number is rising. Around 2.5 billion more people will live in cities by 2050, according to the United Nations, and to accommodate them we’re going to need to build—a lot. 

But this requires vast amounts of energy. The chemical and thermal combustion processes involved in the production of cement, a key ingredient of concrete, accounts for around eight percent of global CO2 emissions. The steel industry accounts for approximately another 5 percent. 

What’s more, construction materials require us to mine the planet’s precious resources. And then, once they’ve served their purpose, they come to account for around one third of the world’s waste. 

In a bid to find sustainable workarounds, scientists and climate conscious entrepreneurs are turning to biology. 

Boitouzet’s process removes that lignin by placing the wood in a reactor, where it is submerged in an alkaline solvent at a high temperature. This causes the lignin molecules to detach, and these are washed away. 

A bio-based polymer is added, which takes the lignin’s place, and—when fixed under pressure to create strong, new chemical bonds with the cellulose—a new material that the company calls “augmented wood” is produced. 

This can take a variety of forms, depending on the polymer. One Woodoo product (called “Solid”) is all about durability: The company says it has the strength of steel and a rigidity 23 times greater than concrete. It also has the benefit of being weather-proof, light, strong, dimensionally stable and easy to machine.

The idea is that Solid could be a bioreplacement for the concrete, steel, and aluminum used in construction. Boitouzet intends to target horizontal structural applications first, as the bulk of those conventional materials are used to create flat surfaces such as floors and ceilings. Solid’s carbon footprint is 229 times lower than aluminum, 149 times lower than steel, and 21 times lower than concrete, based on a life cycle analysis. 

In April 2023, Woodoo raised $31 million to bring its products to market, but that’s not easy. The construction industry is difficult to penetrate because it requires different regulatory approvals in each territory. 

Woodoo’s materials are, however, readily available and easy to integrate in construction systems because they don’t require industry professionals to adopt new methods. There are also indications that building codes and regulations might be accepting of it. California, for instance, has recently approved cross-laminated timber for up to 18-story construction, and New York has approved it for buildings of up to 85 feet tall. 

Boitouzet believes this makes it a no-brainer. “On one hand you have a super emissive material that is non-renewable,” he says. “And on the other you have a material that has stored C02 and it grows next to your house.”

Woodoo has recently started its regulatory process in France and believes the process will take around 18 months. For now, the company must ensure its manufacturing processes are scalable and that its products can approximate the price of the materials they aim to replace. First, they intend to compete with aluminum, because it is relatively expensive. Later, once costs have fallen, they will take on concrete, which is a far cheaper material.

One pressing question is: What will happen to the augmented wood after the buildings have been dismantled? If it’s not going to be reused there needs to be a plan, because otherwise the carbon it stores will be released back into the atmosphere. “Solid is mechanically recyclable and could be ground to be sold as a bio-based composite at the end of the life cycle,” Boitouzet says.

“Everyone in the building industry is now looking for bio-based and low-carbon materials at a cheap price, and it’s difficult to crack,” Boitouzet says. “We can't keep building with the same polluting materials. This is the problem that we need to solve for the planet.”