Wood is ubiquitous in the architecture of British Columbia, where the term "West Coast style" is used to describe a vernacular of wood and more wood. In residential buildings of up to six stories, wood is used for both structure and finishes. In taller residential buildings and in commercial and institutional buildings of more than three stories, wood has typically been limited to finishes, and structure tends to be primarily concrete or steel. That is changing.
Location Vancouver, British Columbia (Point Grey, overlooking the Strait of Georgia)
Gross area 158,770 ft2 (14,750 m2)
Completed August 2012
Cost $57.3 million
Annual purchased energy use (based on simulation) 98 kBtu/ft2 (1,120 MJ/m2), 54% reduction from base case
Annual carbon footprint (predicted) 2.4 lbs CO2/ft2 (12 kg CO2/m2)
Program Offices, research laboratories, classrooms, lecture theaters, museum, café
TEAM & SOURCES
Structural system Structurlam Wood Products
Metal/glass curtain wall Kawneer 1600 series
Composite panel Swisspearl
In 2009 the Wood First Act, which aims to promote climate-friendly construction, became law in the province. It requires that wood be a major element in all provincially funded building projects. Why? One reason is that wood is a renewable natural resource, available locally in abundant quantities, with a very low carbon footprint. According to the Canadian Wood Council, it "has the lowest embodied energy of any major building material and is proven to emit significantly less carbon dioxide than competing materials during the manufacturing process." Another reason might be that forestry is a major player in the provincial economy. Predictably, the B.C. concrete industry has been lobbying for amendments.
If ever there was a site that deserves environmentally sensitive buildings, it's the Vancouver campus of the University of British Columbia (UBC), located on a promontory overlooking the Strait of Georgia. This is the setting for the new Earth Sciences Building (ESB), designed by Perkins+Will. This five-story research, teaching, and office facility of 158,770 square feet is among the earliest projects designed to comply with the Wood First Act. The design team, led by project architect Jana Foit, and the client team, led by campus architect Gerry McGeough and project manager Craig Knight, saw the new law not as a constraint but as an opportunity to innovate. As a result, the ESB is in the vanguard of a new architectural language in which wood is the primary structural material.
The project's specifications include floors of solid timber panels over post-and-beam glulam frames, steel-and-wood hybrid trusses a full floor high and long enough to span a lecture theater, wood chevron braces to resist lateral loads, a monumental cantilevered wood stair, and—arguably the building's most public gesture and tour de force—a continuous exterior canopy of solid timber panels over glulam posts. These engineered-wood products are typically made of Douglas fir.
And yet, nowhere does the building scream wood. Perkins+Will eschewed the local vernacular of exposed wood on the exterior. Instead it used wood with elegant restraint, limiting it mostly to the articulation of structure on the interior. Only one exterior design element—the canopy, which wraps the building on three sides in response to site conditions—is wood. The exterior is otherwise clad in glass, cement board, brick-sized CMUs, and stone, mostly in a monochromatic palette of whites similar to that of adjacent buildings. The result is a subtle and contextually appropriate addition to the campus, rather than one advertising its green quotient with an excess of wood.
The ESB is configured as two perpendicular wings connected by an atrium. The northern wing houses classrooms, lecture theaters, and offices. Its structure is primarily wood. The southern wing houses laboratories, the biggest of which is a showstopping double-height space glazed on three sides to bring in natural light and put research on display. Its structure is primarily concrete. The structural difference between the two wings resulted from user concerns about loading, vibration, and acoustics in the labs. "Loading," explains Foit, "is a function of program, and wood structures can be designed for the same loads as concrete or steel buildings. For vibration and acoustics there was no testing available in North America at the time of design, so the compromise was to make the lab wing concrete and the academic wing wood."
The wood structure of the academic wing consists of an innovative floor assembly coupled with traditional post-and-beam construction. The floor assembly is a sandwich, approximately 8.5 inches thick, of laminated-strand-lumber (LSL) panels (3.5 inches), rigid insulation (1 inch), and concrete topping (4 inches). Each prefabricated panel is 4 feet wide by 22 feet long. A frame of posts and beams, steel at the first floor and glulam wood above, supports this assembly. The exterior canopy employs a similar system of cross-laminated-timber (CLT) panels suspended from a beam above. The joints between the panels are so tight that the canopy appears monolithic for its entire length.
The catch-22 of B.C.'s Wood First Act is that the level of innovation it encourages is way ahead of the province's building code. As a result, the engineers at Equilibrium Consulting had to coordinate a daunting amount of structural, economic, and feasibility research, including extensive ambient-vibration testing (AVT), to demonstrate that the ESB's panelized floor system was structurally sound. Despite a lack of relevant design guidelines, it not only met but surpassed the code's prescriptive requirements.
Foit believes the project's reduced environmental impact makes all this effort worthwhile. By using heavy timber, the structure sequesters over 1,000 tons of CO2, the equivalent of getting 415 cars off the road for a year. "The carbon footprint for the timber-frame construction was less than half the footprint for the concrete-frame construction," she says. And her clients at UBC are happy, despite some initial skepticism about the strength, durability, and cost of wood.
"The users love the building, especially the wood parts," says Foit. "I'm proud that we incorporated many innovative wood products and technologies into this building so it can serve as an example of what is possible for future wood buildings. Now when we bring the idea of wood to the table, we can show our clients what to expect. Before this project, that was not possible because we hadn't used many of these technologies."
The Earth Sciences Building, however, is more than the sum of its technological innovations and low carbon footprint. You can pack a building with a laundry list of green features and still end up with lackluster architecture. But this project integrates those features so elegantly and thoughtfully that it transcends them and rises to the level of art.