By Stephen Wallis
As engineered wood evolves as a construction material, the sky is becoming the limit for timber office and institutional buildings.
Michael Green has seen the future of the building industry, and that future is wood. Lots of wood. The Vancouver-based architect is among the most ardent proponents of what is known as mass timber, prefabricated structural wood components that can be used to construct buildings — even large-scale buildings — faster, with less waste and eventually with less money.
Most crucially, Mr. Green and others say, building with mass timber can ameliorate climate change because it produces less in greenhouse gas emissions than construction with concrete and steel. And wood has the benefit of storing the carbon dioxide trees absorb during their growth, keeping it out of the atmosphere indefinitely.
“Roughly 11 percent of the global carbon footprint is related to what buildings are made out of,” said Mr. Green, whose mass-timber projects include the T3 office building in Minneapolis (the name stands for timber, technology and transportation) and a pair of buildings for Oregon State University’s College of Forestry, including a research and development facility for the school’s TallWood Design Institute.
Over the next 40 years, he added, it is estimated that nearly 2.5 trillion square feet of new construction will be needed to support growth in the world’s increasingly dense urban areas, according to the 2017 Global Status Report issued by the United Nations Environment Program. “If we continue to build the way we are,” Mr. Green said, “we are absolutely not going to meet any kind of climate objective, and we’re going to change our children’s future forever in a pretty bad way.”
While cutting down trees to make buildings may not sound environmentally sensitive, mass timber supporters argue that wood could be harvested from sustainably managed forests.
Increasing numbers of architects, developers, governments, educational institutions and corporations are embracing wood. In Biel, Switzerland, Swatch Group just completed three buildings said to be among the largest timber construction projects in the world. Designed by Shigeru Ban, an architect admired for his innovative use of wood, the complex includes a serpentine company headquarters wrapped in a spectacular latticed timber facade.
By Kira Barrett
North America is on the cusp of a mass timber revolution, and the Waterfront Toronto project is leading the way. But the material faces major obstacles.
Abuilding made primarily of wood conjures public fear of fire, but for a growing number of developers, it evokes opportunity. From constructing towering wooden condominiums, to timber college dormitories, to an entire neighborhood built from trees, experts in “mass timber” are creating buildings of the future.
Sidewalk Labs’ master plan for a futuristic smart city on the waterfront in Toronto includes an entire neighborhood made of wood, called Quayside, with 10 mixed-use building up to 35 stories.
The plan is audacious, considering that in the U.S., there are only 221 mass timber buildings in the works or fully built, according to the American Wood Council’s Kenneth Bland.
In most U.S. cities, mass timber buildings, and specifically tall mass timber buildings, are a rarity, if they exist at all.
But architects, city officials and timber advocates across North America are pushing conventional building codes and public perception because of the drastic impact these structures can have on reducing CO2 through carbon sequestration, compared to traditional concrete and steel.
“I think it’s a big opportunity for a lot of cities out there … The impact on reducing carbon emissions on earth could be dramatic,” Karim Khalifa, director of buildings innovation at Sidewalk Labs, told Smart Cities Dive. “And that gets me excited.”
What is mass timber?
One of the biggest obstacles for city officials is understanding the material. They are more than buildings made of wood — they’re defined by their structure. Steel or concrete buildings with wood accents don’t count, according to Andrew Tsay Jacobs from architecture firm Perkins and Will.
Mass timber buildings use solid wood panels to frame a building’s walls, floors and roofs, creating structures that can reach at least 18 stories, as is the case with the tallest mass timber building in the world in Norway. But these buildings aren’t just pure wood. Mass timber construction utilizes engineered wood, or panels glued together, and there are several types: cross-laminated (CLT), glue-laminated and dowel-laminated timber, with CLT being the most common.
While shorter wood buildings have existed for centuries, CLT panel technology is relatively new. It was developed in Europe in the 1990s, the material was only added to the international building code in 2015. Even then, all-wood buildings were capped at six stories, though that will change to allow taller structures in 2021.
AN has mapped the schools, organizations, and manufacturers across the U.S. and Canada that are powering the domestic timber boom.
The timber industry has long thrived on its small-scale, local nature due to the sourcing of its materials as well as the limits on project size set by the building code. With this has come a good deal of fragmentation and disorganization, so we decided to map out the different schools, organizations, and manufacturers that are leading the way in the research and development of mass timber across the United States and Canada.
By Oscar Holland
Stefano Boeri’s tree-covered towers in Milan won critical acclaim. Now he’s taking his urban forests global.
Architect Stefano Boeri has always been obsessed with trees. The Italian traces his fascination back to a novel he read as a child, “Il Barone Rampante” (“The Baron in the Trees”), in which a young boy climbs up into a world of trees and vows to never to return.
“I think trees are individuals,” Boeri said in a phone interview. “Each has its own evolution, its own biography, its own shape.”
Unsurprisingly, there is child-like wonder to the architect’s best-known building, Il Bosco Verticale, or the Vertical Forest. Built in his home city of Milan, the celebrated complex teems with greenery, its facades transformed into living, breathing organisms.
The project’s two residential towers — measuring 80 meters (262 feet) and 112 meters (367 feet) respectively — play host to around 20,000 trees, shrubs and plants. They spill out from irregularly placed balconies and crawl up the structures’ sides. By Boeri’s estimates, there are two trees, eight shrubs, and 40 plants for each human inhabitant.
The purported benefits of this garden architecture transcend aesthetics. Greenery, supposedly, provides shade to apartments, psychological benefits to residents and a home to wildlife. (There are, Boeri said, “hundreds of birds, more than 15 different species” nesting on the towers’ various floors.)
But the architect’s proudest claim is that the buildings absorb 30 tons of carbon dioxide and produce 19 tons of oxygen a year, according to his research, with a volume of trees equivalent to more than 215,000 square feet of forestland…
In September, Vertical Forest was named among four finalists for the RIBA International Prize, a biennial award honoring the world’s best new buildings. Amid the plaudits, Boeri claims the project’s real success is that it serves as a prototype.
The architect has far more ambitious designs. His firm has already unveiled plans for new Vertical Forest buildings in European cities including Treviso in Italy, Lausanne in Switzerland and Utrecht in the Netherlands.
In the Chinese city of Liuzhou, Guangxi province, he has masterminded an entire “Forest City,” scheduled for completion in 2020, which comprises tree-covered houses, hospitals, schools and office blocks over a sprawling 15-million-square-foot site. (Boeri said that he’s also been approached about producing similar “cities” in Egypt and Mexico.)
BY EILLIE ANZILOTTI
A new tower will have greenery lining the balconies and roofs to clean up the air and provide a new environment for pollinators and humans alike.
Toronto has long been serious about its urban canopy. The Ontario city is already home to around 10 million trees, which cover around 26% of the city. The current mayor, John Tory, wants to grow that to 40%.
Brisbin Brook Beynon, a local architecture firm, is already giving the city a leg up on that goal, albeit in an unconventional way: a 27-story residential building that will be covered with around 450 trees, growing on its balconies and roofs. This “vertical forest,” as BBB terms it, takes inspiration from the Bosco Verticale–residential towers in Milan that went up in 2014 with as many as 11,000 plants lining the sides. Since then, copycat buildings have been built in cities like Nanjing and in Taiwan–designed to combat pollution and prove that green space does not need to be limited to the ground. This latest iteration could open as early as later next year.
For Brian Brisbin, principal at BBB, bringing the vertical forest concept to Toronto aligned perfectly with the mayor’s goals for increasing tree coverage. And when he began researching the concept by studying the Bosco Verticale, he realized that all of the technology that enabled the Milanese building to function originated in Canada and North America. “That felt fairly profound,” Brisbin says.
And it also, Brisbin says, made bringing the concept to Toronto feel much more feasible. “We have a lot of depth of specialty in this area in Toronto, with horticultural and agricultural universities and research facilities,” he says, “and we’ve brought a lot of together to take a very science-based approach to developing this project.”
by Jack McManus
Space Popular’s design gathers service functions into a central prefabricated core (resembling a Nordic hearth) that DIY-ers can build their own house around.
Solutions from the past can often provide practical answers for the problems of the future; as the London-based design and research firm, Space Popular demonstrate with their “Timber Hearth” concept. It is a building system that uses prefabrication to help DIY home-builders construct their own dwellings without needing to rely on professional or specialized labor. Presented as part of the ongoing 2018 Venice Biennale exhibition “Plots Prints Projections,” the concept takes inspiration from the ancient “hearth” tradition to explain how a system designed around a factory-built core can create new opportunities for the future of home construction.
Realized in the form of a brightly-painted model in the exhibition space at Serra dei Giardini, the Timber Hearth system gathers all the service functions, appliances, and fittings that require professional installation in typical residential buildings and contains them within a prefabricated hearth-like structure.
Fabricated in a factory and sized for shipping in one piece, the core is then installed on site and connected to service grids. After that, the remaining construction (including building the floor platforms, partition walls, facade, and roof) can be completed by the homeowners, either by traditional or contemporary timber-frame methods. According to the designers, this affords reasonably-equipped makers the flexibility, freedom, and affordability to build their own perfect home.