They say the age of steel and concrete is replaced by the age of wood: the first wooden multi-story office building in the USA T3 - "Timber, Technology, Transit" - was implemented by the Canadian bureau Michael Green Architecture in collaboration with local architects from the DLR Group, engineers from Magnusson Klemencic Associates and specialists in structural wood Structure Craft.
The client, the development company Hines, wanted to create a unique office that would attract the attention of companies in the creative and high-tech sectors. According to the creators, the building was supposed to combine the "reliability" characteristic of historic buildings with innovation, environmental friendliness, sustainability, bright open spaces and common spaces for residents. Therefore, in contrast to the modern timber buildings (
the previous office building of Michael Green in Vancouver or, for example, the Sky headquarters in London), on the facades of T3 there are no notorious "staggered windows" or large glazed surfaces, only strict geometry, copying the forms familiar to American architecture of the 19th - first half of the 20th century … Time ironically rearranges the terms: the ancient Greek experiment to reflect the old wooden structure in the stone decoration echoes in the attempt of the wooden structures of the XXI century to imitate the visual series characteristic of the traditional materials of the past centuries.
The building has an area of 20,810 sq. m was erected in record time at a speed of about 2,780 sq. m of area per week. 16 720 sq. m of the supporting frame were assembled in 9.5 weeks by efforts
Structure Craft, responsible for the design of timber structures, their production and installation on the construction site (animated construction process - here).
A post-beam frame with a 6x7 grid of glued spruce columns rests on the reinforced concrete structures of the first floor, and the overlying floors are assembled from NLT panels (like this
the assembly process was in progress). The choice fell on NLT (Nail Laminated Tiber) - panels made of glued beams connected by metal pins - due to the lower cost of their production and, oddly enough, "tradition". The existing building codes of both the United States and Canada (IBC 602.4.6.1 and NBCC 3.1.4.6 4b / 6b) allow the use of this material for floors, while for buildings from CLT, officials have not yet rewritten their requirements, and for the construction of another high-rise building each just make a special exception to the rule.
The total weight of the resulting structure turned out to be 30% less than the alternative steel system and 60% less than reinforced concrete: this difference not only increased the speed of construction and simplified the assembly process (powerful tower cranes were not needed), but also reduced the volume of the foundation part, which significantly saved money. The cost of this wooden frame is close to the steel one, but at the same time it does not require additional fire protection: the fire resistance of the building is more than three hours due to the property of wooden products of large cross-section
do not lose bearing capacity for a long time after a fire.
In the interiors of six office floors, wooden structures shine with light surfaces: according to the authors, through the brown facades of Corten steel, the rectangles of windows should glow like a city lighthouse, and the interior space, due to the lack of processing, should be warm, “ours”. NLT-panel bars are made from trees killed by the mountain pine beetle -
an epidemic that is changing the landscape of North American forests. The wood affected by this beetle is sometimes covered with blue mold, which, although it is one of the causes of death of the plant, does not affect the technical and operational characteristics of the material collected and dried in time and is not dangerous to humans. These imperfections, so inherent in naturalness, give a special character to the space, say the architects of the project.
Michael Green Architecture claims that T3 is the first high-rise timber structure erected in the United States in the last hundred years, but do not forget about a slightly earlier history. The Butler Square Building is located literally on the next street. It is a 9-storey building with an area of 46 450 sq. m was built in 1906 as a warehouse, and behind its heavy brick facade is a powerful wooden post-and-beam frame with a 4x5 grid. This skeleton of solid wood of Douglas fir has just passed over a hundred years.
T3, making a curtsey towards the local historical heritage and local traditions, merges into the existing development, not pretending that he is from an unpredictable future. The task of giving the impression of "reliability" has been solved. Well done, Mr. Tall Wood.
