By design, a new mid-rise building in Prince George, B.C., breaks many conventions of commercial construction.
At 29.5 metres, its height alone makes the Wood Innovation and Design Centre the highest contemporary wood structure of its type in North America – a record soon to be broken by others. The $25.1-million centre also stands out for its embrace of engineered wood: thick panels, columns and beams of so-called mass timber, sturdier and more fire-resistant than lightweight wood frame construction.
Built as a showcase for wood's potential in mid-rise and taller buildings, the provincial government-owned centre houses academic and research programs at the University of Northern British Columbia and corporate offices. Its opening last fall comes as architects and others look to push the traditional boundaries of wood as a structural material in commercial construction. See earlier story: Six-storey wood buildings 'a game-changer.'
"The building is a very important milestone and stepping stone as we work our way higher into the taller wood building arena," says Michael Green, principal of Vancouver-based Michael Green Architecture and the centre's architect. He used engineered wood products for the centre's stair and elevator core and, for the floor assembly, eliminated a layer of concrete typically needed to muffle sound.
"The hardest part of this process of introducing a new way to build is not the engineering; it is shifting the public's perception of what is possible," adds Mr. Green, co-author of the 2012 industry-financed study, The Case for Tall Wood Buildings.
Climate change is one factor behind the rise of wood as a competitive rival to concrete and steel, the typical energy-consuming components of taller buildings. Mr. Green likens the shift to adopting healthy eating habits.
"What we want to do is reduce the things that we know aren't good for us, like steel and concrete, but that doesn't mean we get rid of them completely," he says. "We are just reproportioning these materials in buildings and not trying to say that one is exclusive over another."
Also raising wood's profile is an expanded menu of engineered products, first developed in Europe a decade ago but now manufactured in Canada. One recent arrival is cross-laminated timber, engineered in various panel thicknesses of 2 x 6 planks, glued cross-wise, often pre-cut and assembled on site faster than traditional materials.
Architects also use laminated veneer lumber (thin strips glued together), laminated strand lumber (a largely warp-free composite material) and glue laminated timber, an established product known for its steel-rivaling strength and used for horizontal beams or vertical columns.
"In just 15 years, wood has repositioned itself as a high-tech material," says Vancouver engineer Eric Karsh, a principal at Vancouver-based Equilibrium Consulting Inc., and Mr. Green's co-author of the tall wood building study. "People are starting to see it as a high-tech material and it is no longer something you use in a rough or inefficient manner," he adds. "We have shown that wood can be used in just about any building type so now it is just a matter of weighing the pros and cons."
Vancouver-based McFarland, Marceau Architects Ltd., with a history of working with natural wood, six years ago became an early adopter of cross-laminated timber, whose structural robustness allows for large spans without beams.
"There is an enthusiasm here in Canada at the moment for increased use of wood in buildings following the European lead," says principal Marie-Odile Marceau. "No question, [there is] a wider palette enabling us to do architectural gestures," she adds, as with cantilevered canopies.
In 2009, her firm was selected for the University of British Columbia's bioenergy research and demonstration facility, situated in a tight space surrounded by trees. "The use of CLT [cross-laminated timber] and other engineered wood products, such as large beams and columns, allowed us to build that facility," she says.
Meanwhile some critics, mainly in the concrete and steel industries, question the fire safety of taller wood buildings. But a study by the University of the Fraser Valley, citing research by others, noted that "tall wood buildings can be designed to provide a minimum two-hour protection rating similar to most current [building] code requirements."
In cost comparisons, mass timber products can be more expensive than concrete or steel, architects say, but a client's wish for an environmentally-friendly building or one that captures the warmth of exposed wood can tip the balance.
"That's when the stars align," says Normand Hudon, associate architect at Quebec City-based Coarchitecture, which used cross-laminated timber for a multi-sport facility at Laval University in 2012. "The university wants to be attractive to students and when you have a warm and welcoming sports facility it helps to attract the best students."
In 2011, his firm won a competition that called for innovation and sustainable development in the design of the Quebec City offices of GlaxoSmithKline Inc. Built of glue-laminated timber, the three-storey carbon-neutral building won the architectural innovation award of excellence from the Royal Architectural Institute of Canada in 2013.
The opportunity to work with cost-competitive wood products fuels experimentation, says RAIC executive director Ian Chodikoff. "The more companies in Canada that innovate with products, the more opportunities there are for architects to become innovative in their work."
Three years ago, Quebec-based Nordic Engineered Wood Products became one of two Canadian suppliers of locally-produced cross-laminated wood. In 2013, the company's product was used in a six-storey condominium in Quebec City believed to be the tallest mass timber multi-residential building in the province. A six-storey condo project was just announced for Montreal.
Company spokesman Frédéric Verreault says the adoption of cross-laminated timber for taller buildings entails a shift in thinking by project developers. "It's a matter of a change of culture," he says. "Any change in thinking has to be made one step at a time."
Similarly, there is "a learning curve" to understand the structural and fire-resistant properties of engineered wood, says Conroy Lum, a research leader on the use of wood in building systems for FP Innovations, a forestry industry research organization. "It costs money to get on that learning curve, train staff and acquire the equipment."
That was the experience of Toronto-based LGA Architectural Partners, which last year won a contract for phase two of Laurentian University's school of architecture, with one wing built of glue-laminated and cross-laminated timber. The project marks the first large-scale use of cross-laminated timber in a public building in Ontario, according to the Sudbury university.
"It was a real accelerated learning curve," says firm partner David Warne, citing the need to understand (and explain to others) the implications of working with cross-laminated timber.
Though City of Sudbury building department officials were receptive, says Mr. Warne, "we had to convince them this new product that no one had tried was suitable for the structure and would not collapse."
He is enthusiastic about adding engineered wood to the architect tool-box. "We will see a bit of a renaissance in wood construction in Canada," he predicts.
Mr. Green, Canada's leading proponent of wood in taller buildings, is even more emphatic.
"This is a tidal wave coming at us," he says, citing dozens of projects on the go across North America.
Examples of tall wood development around the world:
East London: Nine-storey apartment building.
Vancouver: A proposed 16- to 18-storey wood tower for academic programs and student residences at the University of British Columbia.
Quebec City: Proposed 13-storey condominium is a demonstration project.
China: Canadian forestry industry representatives signed a memorandum of understanding last November with China to test the feasibility of building a six-storey wood-frame building and a 12- to 15-storey tower of wood or hybrid systems in Shanghai.
Norway: Fourteen-storey apartment tower (under construction) in Bergen.
Sweden: Developers have plans for a 34-storey tower of wood by 2023.
Melbourne: At 10 storeys (32.1 metres), a timber apartment building is the tallest in the world, for now.