By: CBC News
The search for ways to build greener, more energy-efficient buildings has triggered a 21st century version of the old skyscraper race, but these contestants aren’t made of concrete and steel.
This week’s Globe Conference on sustainability in Vancouver will hear how some municipalities, including two B.C. cities, are pushing the boundaries of building high with wood.
“Why wood? Wood is sustainable. It’s a renewable resource,” said the University of British Columbia’s John Metras, standing in front of what will soon be the tallest building of its kind.
The future site of UBC’s 18-floor Brock Commons student residence is a hive of activity on the campus these days.
When it’s completed in 2017, it will be one of the tallest buildings in the world made mostly of wood, UBC says.
Wood is still slightly more expensive than concrete and steel, but UBC says there’s another benefit. Not only do wood buildings create fewer greenhouse gas emissions, they actually store carbon dioxide as well.
“A building like this, the calculation we’ve done, is the equivalent of taking 480 cars off the road for a year,” said Metras.
“This is really the evolution of wood structures.”
Wood construction growing worldwide
In Japan, Australia, and all over Europe, engineers are using more wood to reduce the high greenhouse gas emissions created during concrete construction.
New wood engineering technology and super-strong bonding means it’s possible to create sheets of plywood-like panels that can approximate the strength of steel.
“This is the first new way to build a skyscraper in a century and our building codes just didn’t imagine it would come up,” said Vancouver architect Michael Green.
Green is a world leader in wood building design, and the architect of the tallest contemporary wood building in North America, theWood Innovation and Design Centrein Prince George, B.C.
The eight-storey building was completed in 2014 using wood and wood-engineered products from around B.C.
“These buildings have to perform to the same standards as steel and concrete, and we know they can,” said Green.
“By saying we are going tall, it’s a chance to expand our imagination and open up a conversation that wasn’t happening.”
Green’s company is also on the cutting edge of wood highrise construction in Europe, where he’s proposed what would be the largest wood-supported tower on earth, a 35-storey skyscraper in Paris.
“The game changer is new, advanced wood products,” said Green.
“We used to cut down big trees and use big pieces of wood. Now we’re cutting down smaller trees, gluing them together and making them incredibly strong, so technically we can build extremely tall,” he said.
“We’ve done technical studies that you can rebuild the Empire State Building in wood, 110 storeys tall. It actually is possible.”
Overcoming fire risks
The risk of fire has been an enormous problem for those trying to build taller with wood.
In the 1800s, after a large fire in London and the three-day blaze that destroyed much of Chicago, wood was shunned for tall structures, and the perception that wood buildings were unsafe became a barrier to innovation.
But Green says technology is overcoming that too, especially by using massive pieces of wood, which he says are massively resistant to fire and also safe in earthquakes.
“They burn very, very slowly and char and insulate themselves because of their size,” said Green.
“Most Canadians live in wood homes. Most Canadians don’t return home from work wondering if their home is still there or has burned down, because we’ve learned over the last 30 years how to make homes fire-safe and now these large buildings [are] fire-safe.”
The majority of Canadian building codes still limit wood structures to four or six storeys, but increasingly planners are looking at the wood innovations and granting exceptions.
Green says it’s an acknowledgement that ever-taller wooden buildings may be part of the answer to climate change.
“We talk about energy and the important shift to renewables. The same conversation is happening in buildings.”
By: CBC News