Michael Greene, a Canadian architect and the world's most popular advocate for high-rise timber construction, has erected a 29.5-meter office building in Prince George, British Columbia. 250 people were involved in the design and implementation of the facility, from logging specialists and environmentalists to carpenters, engineers and designers.
The resulting 8-story Wood Innovation Design Center is a space for just this kind of collaboration; it brings together researchers, designers and engineers who work to harness the building potential of timber. On the 4,820 m2 of the new building, there is an educational center on the lower floors where master students from the Faculty of Integrated Design in Wood at the University of Northern British Columbia study: on the first floor there is an open exhibition space, university research laboratories, a lecture hall, on the second - classrooms and a terrace. The upper floors are occupied by the offices of companies operating in various areas of the "wood" industry.
Thus, the new building simultaneously contains a “process” where theoretical and applied research, training, practice and direct work with the material merge, and is the “result” of this process, demonstrating the aesthetic and constructive possibilities of multi-storey timber construction.
The load-bearing frame of the building is a post-and-beam structure made of glued laminated timber, a core of stiffness, stair-lift shafts - cross-laminated timber, stairs, a canopy over the entrance to the building and floors - panels of glued veneer (laminated veneer lumber) and laminated strand lumber, enclosing structures - oriented strand board sandwich panels. Such a structure helps to achieve two main objectives of the project: it has the necessary load-bearing capacity and stability in relation to lateral loads, and compared to other building materials has an unusually long life cycle: due to the lack of reinforced concrete in the above-ground part of the building, wooden elements can be easily disassembled and used in other objects.
All columns and the main part of the beams are glued, except for the beams above the atrium of the first floor, which carry the main load: they are made of PSL timber from parallel strand lumber. The dovetail fastening of the beam to the column is carried out with a special aluminum connector, pre-assembled at the factory: this simplifies the installation process at the construction site, and the connection receives fire protection due to the thickness of the wooden element, which surrounds the metal on all sides.
One of the difficulties that had to be faced during the implementation of the project is the local building code, which prohibits the construction of residential buildings with a timber frame above 6 floors and public buildings above 4. But for this project, an exception was made when, during real tests, the authors were able to prove to two state commissions of different jurisdictions (the city of Prince Jones and the province of British Columbia) that the CLT panel joints have the necessary fire resistance.
Traditionally, wood is protected by the method of full or partial encapsulation - by covering wooden elements with non-combustible materials, for example, a gypsum plaster layer, but in this building it was necessary to leave the wooden surfaces open, therefore, for the sake of fire protection, all sections were increased: they began to far exceed the required structural dimensions, but the resulting the additional layer increased the time of maintaining the integrity of the structure during combustion.
Visually, the building becomes more and more permeable as it turns to the south: from a completely opaque wall in the north to solid glazing in the south. In a northern climate, this approach optimizes the flow of natural light and improves the insolation of the interior. External enclosing structures - energy-efficient sandwich panels made of oriented strand board with a thermal insulation layer in the core. The cladding is made of cedar siding, most of which was previously charred, due to which it got its black color. Wood charring is a traditional fire and biosecurity practice in Finland, Japan and Switzerland, and a building has now appeared in North America to demonstrate this technology.
Transparent curtain walls are made of 3-layer glass, and instead of the usual aluminum for frames, LVL-beams were used: experts say that this is the first practice of using wood for such large glazing surfaces.
Towards the street, the building opens with a massive canopy supported by yellow cedar columns. According to Michael Green, the challenge for the architects was to make the building not only technically innovative, but also with a simple beauty that stems from the naturalness of wood and skillfully executed details.
Modern high-rise structures are made predominantly of concrete and steel - materials that, according to Michael Green, are responsible for about 8% of all greenhouse gas emissions. However, using “responsibly” harvested carbon sequestering timber (see our review of multi-story timber houses for more on this).
here), reduces emissions and is one of the most effective methods for preserving the planet's ecosystem, says Green. In terms of “responsibility,” the project involved forestry and environmentalists growing planting material in greenhouses and planting several hectares of seedlings to compensate for the wood used in construction, accelerating the natural regeneration of forests.
Michael Green's goal was to inspire officials, developers and builders: “We wanted to show the world the future of wood construction,” says the architect. However, ideological opponents defy his charm, and argue that the Tree Center is the result of the activity of the "timber lobby" of the Canadian forest industry, since the project was supported by the British Columbia government and, accordingly, was implemented with taxpayer funds. A note worthy of discussion: the construction of a commercial building at the expense of the state budget is a somewhat dubious undertaking. However, judging by the professional affiliation of the critics, it can be argued that the position of the "reinforced concrete lobby" has been somewhat shaken, and the BC Ready-Mixed Concrete Association foresees the possibility of expanding public investment in wood construction.
