London currently faces both a shortage of housing and an abundance of greenhouse gas emissions, preventing the city from reaching its sustainability and affordability goals. But last week, a novel solution proposed to Mayor Boris Johnson would solve both these problems with an engineering feat that may seem too good to be true; an 80-story, eco-minded wooden skyscraper that would provide hundreds of units of low-cost housing while becoming the second-tallest building in the capital behind the Shard.
A joint project between Cambridge University’s Centre for Natural Material Innovation and PLP Architecture, the proposed wooden skyscraper would tower over the current record holder for tallest timber building, the 14-story Treet apartment building in Bergen, Norway. The structure, which would be erected in a courtyard of the Brutalist Barbican estate, would rise 300 meters, and be the centerpiece of a 1 million-square-feet mixed-use development. The remaining courtyard, and a series of rooftop gardens atop the tower, would be landscaped give the appearance of greenspace being lifted from the ground.
“If London is going to survive, it needs to densify,” says Dr Michael Ramage, Director of Cambridge’s Centre for Natural Material Innovation. “One way is taller buildings. We believe people have a greater affinity for taller buildings in natural materials rather than steel and concrete towers. The fundamental premise is that timber and other natural materials are vastly underused and we do not give them nearly enough credit. Nearly every historic building, from King’s College Chapel to Westminster Hall, has made extensive use of timber.”
According to PLP Partner Kevin Flanagan, choosing cross-laminated timber over standard glass-and-steel construction has its advantages. The structure would take up roughly the same dimensions and space as a traditionally constructed tower, yet would weigh significantly less and take less time to build, since the plan calls for a series of quickly assembled modular panels.
“You’ll have more density of material, but a quarter of the weight,” Flanagan says of the proposed scheme, which would also provide a significant cost savings. “There would be a larger base, to provide resistance, but the general idea would be stacking a series of boxes. Think of it like the Sears Tower; it’s still using the same idea of bundled columns, like a pack of cigarettes.”
Flanagan thinks that, despite hesitancy from some about using wood as the structural skeleton for such a massive project—even though designers assure that it meets all applicable fire codes—the trend towards tall timber construction is growing, and may usher in a new type of architecture that takes advantage of the unique qualities of engineered timber. With London in a serious bind due to a lack of affordable housing, more unorthodox ideas may be part of the way forward.
“I feel like we’re on a crest of interest,” he says. “There’s a pleasing sense I get from people that it’s not a totally wacky idea. It’s more, 'Why didn’t we think of that?'”