Brock Commons Tallwood House, Vancouver

According to the website naturallywood.com the wood industry in British Columbia sees enormous potential in solid timber structures. The structural properties are comparable to a steel or reinforced concrete construction, but they clearly are superior to more traditional construction materials in terms of sustainability and construction time. In particular, large buildings can be efficiently and economically produced in wood.

The 18-storey timber construction in the Brock Commons campus demonstrates the efficiency of the building material with around 15,000 m2 of floor space. In 2009, local authorities increased the maximum number of storeys from four to six in order to increase the height of wooden buildings. For the 53 m high dorm this change was not enough. However, the campus has its own building regulations and the Canadian building laws allow for exceptions. This made it possible to use timber to create these new dimensions, but the requirements for earthquake safety and fire safety were more stringent than for a steel or reinforced concrete construction.

The approval process was time-consuming: in addition to a peer review, a committee of fire protection experts, scientists, authorities and firefighters assessed the construction. To increase the resistance of the wooden structure against fire, the wooden components are packed in plasterboard. Only on the top floor, which serves as a recreation room for the students, the timber is visible and provides a window into the construction method used to create the skyscraper. A redundant system supplies the sprinkler system with water and electricity even if the connections to the public network are interrupted.

The supports of the modular timber construction consist of laminated beams that are 26 x2 6 cm. They are arranged on a floor plan of 15 x 56 m, in a grid of 2.85 x 4 m. On the columns lie ceiling slabs of cross-laminated timber (CLT), the five layers of theses slabs create a total thickness of 16.6 cm. The staggered two- and three-field plates are biaxially stretched, thus enabling a ceiling completely without joists. In addition to a quick installation, this has the advantage that the technical building equipment can be easily installed. The shear bond between the individual CLT plates is produced with a recessed 3-layer plate. This creates a statically usable disk out of the individual plates. All horizontal forces (wind, earthquakes) are transmitted via steel bands from this disc into the concrete tower. The wooden supports take away the vertical loads and pass them on to a reinforced concrete structure on the ground floor. The building was built within a very short time. Every week, the construction grew by two floors; the total build took only 9 and half weeks and was completed ahead of schedule.

The building’s expression adopts the sober and modernist language of the entire campus. The façades are made of Canadian standard steel frame construction, with a panel of high-pressure wood and paper laminate panels, with alternating large Trespa panels and floor-to-ceiling windows. Corner glazing dissolves the volume of the surfaces and a metal cornice crowns the building. A sunshade, made of CLT, adds the warm atmosphere of the outside common areas. The vestibules of the elevators are clad in the same way as the facades in the student housing area. The corridors feature wooden doors and colour accents in umber and ochre. The interior of the 305 studios, and four larger units, are economical and simple: the warm colours of the carpets compliment the white gloss surface of the desks. The view of the ocean and the mountains is spectacular.

In addition to the transfer of industrial know-how, ambitious sustainability goals are being pursued.  The LEED Gold label is being achieved and the standard ASHRAE 90.1-2010 (Energy Standard for Buildings Except Low-Rise Residential Buildings) must be fulfilled. Compared to a conventionally constructed building, the new dormitory saves 25% of grey energy and consumption from the operation. The building owner has already made an important contribution to the protection of the environment with the choice of construction material: the solid wood construction saves a volume of 2,650 m³ of concrete, which corresponds to an equivalent of around 500 tonnes of CO₂.

The dormitory is an important pilot project for solid construction in wood. In order to make the ecological qualities of this type of construction a relevant factor, however, it has to be used in a wide variety of scales and uses – both in visible applications and in timber construction. To promote this construction, the project was funded by the TallWood Buildings Demonstration Project Initiative, with contributions from the Province of British Columbia, the Binational Softwood Lumber Council and FP Innovations.