World-leading fire safety expert José Torero has told Dezeen he is "extremely concerned" about mass-timber buildings being constructed around the world.
As part of a feature on fire safety, Torero claimed that a lack of consistency in the competency of people designing and constructing mass-timber buildings runs the risk of a "catastrophic" fire event.
"My concern is that there are no proper standards of competency when it comes to the design of mass timber buildings," he said.
"And the potential consequences that you can have from a fire in a poorly designed building can be catastrophic," he continued.
"So in that context, yes, I'm extremely concerned about existing buildings, as much as future buildings that are being built."
Timber "perfectly safe if done right"
Torero is a professor of fire safety engineering and building design at University College London, where he is head of the Department of Civil, Environmental and Geomatic Engineering.
He supported official investigations into some of the world's most high-profile building safety incidents, including the World Trade Center collapse on 9/11 and the Grenfell Tower fire. He has also been studying the fire safety of timber buildings since the late 1990s.
While Torero does not believe that mass-timber poses an inherent fire safety risk, he expressed fears that varying levels of knowledge and skill in using the material could mean some buildings are of a poor standard.
"Timber can be perfectly safe if it's done right," he told Dezeen. "This is not a technological or technical problem, it is fundamentally a problem of competency."
"The problem is whether [building designers] are competent enough to be able to make a proper assessment, and that is a much, much more complicated question."
In addition, he warned that a large building fire in a timber building would be more likely to spread to surrounding buildings, increasing the potential risks.
"The ultimate consequences in the case of a timber building can be much more significant than in the case of a concrete or steel building," he said.
Engineered wood products such as cross-laminated timber are composed of layers of wood joined together to form strong panels or beams that can be used as structural materials in tall buildings.
Having been first developed around three decades ago, they are rapidly growing in popularity thanks to timber's ability to sequester large amounts of carbon and therefore dramatically reduce the carbon footprint of new buildings compared to concrete and steel.
However, Torero is concerned that fire safety issues are being sidelined in the push to embrace mass timber.
"It's not prioritised at all," he said. "And nevertheless, we're moving at a speed that is extraordinary. And to me, that is just a reflection of pure ignorance, and we're entering a space where we are taking risks blindly."
"What if the next big fire is in a timber building?"
Other mass timber and fire safety experts voiced similar concerns.
"I know there are some where I would have concerns about them," said Arup principal David Barber, a specialist in the fire safety of mass-timber buildings who was the fire engineer on the world's tallest timber structure, Ascent Tower in the United States.
"It would be people who haven't understood what they don't know, people who haven't been experienced enough with mass timber to have spent the time and the effort to actually find out the stuff they don't know."
"What if the next big fire is in a timber building?" added British architect Joe Giddings. "I have given it lots of thought. It definitely worries me."
"We shouldn't play down the fire safety concerns"
Giddings is the UK networks lead at Built By Nature, an organisation dedicated to accelerating timber construction across Europe, and a co-founder of the Architects Climate Action Network (ACAN).
He also played an active role in ACAN's Save Safe Structural Timber campaign, which opposed a UK government proposal to include timber in a ban on combustible building materials in residential buildings above four storeys.
"If we breed false confidence without competency becoming widespread, we're playing a dangerous game," he added. "We shouldn't play down the fire safety concerns."
Dezeen is currently running the Timber Revolution series, which explores the potential of mass timber and whether its adoption on a greater scale can help lead the world to a more sustainable future.
The top photo, for illustrative purposes only, is courtesy of Shutterstock.