Vorarlberger Holzbaupreis 2019

Construction Underway on
World’s Tallest Timber Tower

Construction of the 18 storey Brock Commons Student Residence at the
University of British Columbia in Vancouver, Canada got underway in
November 2015. When completed in the summer of 2017 the 53m tall high-rise
building will provide housing for 404 students and be the tallest mass wood
hybrid building in the world.
The $51.5 million project was designed by Acton Ostry Architects of Vancouver,
BC with Architekten Hermann Kaufmann of Austria as tall wood advisors, Fast
+ Epp as structural engineers and GHL Consultants Ltd. as the fire science and
building code consultant.

A key mandate for the innovative project is to demonstrate the viability of mass
wood structures for BC’s development and construction industries. This has
been achieved with a hybrid design that combines the benefits of mass wood
and concrete to achieve an economical structural system that is comparable in
cost to that of traditional all concrete and steel structures.

Structural System

The hybrid structural system is comprised of a one storey concrete podium, two
concrete cores and 17 storeys of mass timber topped with a prefabricated steel
beam and metal deck roof. Vertical loads are carried by the timber structure
while the two concrete cores provide lateral stability.
Glulam columns with steel connectors provide a direct load transfer between
the columns and support 5-ply cross laminated timber (CLT) panels on a 2.85m
x 4.0m grid that acts as a two-way slab diaphragm, similar to a concrete flatplate
slab. The robust structure will be the first in British Columbia to be built to
meet new seismic design requirements for the 2015 National Building Code of
Canada.

Prefabricated Facade

The prefabricated facade is made up of 8m long steel stud frame sections
with pre-installed windows. The cladding is high-pressure laminate panels
consisting of 70% wood-based fibers that will be arranged to create a pattern
of blonde wood and charcoal-coloured vertical striations. Glazing wraps the
corners to dematerialize the edges and a metal cornice crowns the building.
An extensive 58m long CLT canopy runs the length of the building base, which
is wrapped with curtain wall glazing and translucent blue glass spandrel panels.
It is projected that the prefabricated mass wood hybrid structure and facade will
be erected at a rate of at least one floor per week, resulting in time savings for
the overall construction process.

Construction Strategy

A key design and construction strategy was the recognition that the level of
prefabrication available in British Columbia is not as extensive as that which
is available in Europe. However, the speed and skill of high-rise residential
trade contractors in Vancouver is considerable. In response, the design
and construction approach takes best advantage of local prefabrication and
subtrade capabilities. Primary prefabricated components are the CLT slab
panels, glulam columns, steel connectors and the facade.
To test the speed and efficiency of the erection of the mass wood hybrid
structural system, a full-scale two-storey proof of concept mock-up was
constructed in July 2015. Erection of the structure went smoothly and assembly
proved to be faster than was initially projected.
After the first few floors of the mass wood structure and the facade have been
erected, work will begin on the building systems and components housed inside
the superstructure. The mechanical, electrical and sprinkler systems will be
similar to those used for other student resident buildings on the UBC campus.

Sustainability

Brock Commons has been designed to target LEED Gold certification and to
conform to ASHRAE 90.1-2010. The building will connect to the UBC district
energy system and is projected to achieve up to 25% energy savings over a
typical building of the same use.
Advances in wood technology and manufacturing make tall wood buildings not
only possible but also safe and cost effective, while providing a way to lessen
the carbon footprint of the built environment. For Brock Commons the carbon
stored in the mass timber structure, plus avoided greenhouse gas emissions,
results in a total estimated carbon benefit of 2,563 tonnes of CO2, which is
equivalent to taking 490 cars off the road for a year.

Architect
Acton Ostry Architects Inc.

Tall Wood Advisor
Architekten Hermann Kaufmann ZT GmbH

Structural
Fast+Epp

Fire Science | Building Code
GHL Consultants Ltd.

Building Science
RDH Building Science

Mechanical | Electrical | Sustainability
Stantec

Virtual Design Modeling
Cadmakers Inc.

Energy Modeling
EnerSys Analytics Inc.

Acoustics
RWDI

Landscape
Hapa Collaborative

Civil
Kamps Engineering Limited

Geotechnical
Geopacific Consultants Inc.

Construction Management
Urban One Builders

Project Management
UBC Properties Trust

Owner
University of British Columbia

Mit seinen 18 Stockwerken und 53 m Höhe ist das Studentenwohnheim der British Columbia University, ein Bauherr, der seit je avantgardistische bauliche Lösungsansätze fördert, die höchste Holzkonstruktion der Welt. Bei dieser Art von Aufgaben ist Brandschutz ein besonders heikles Thema. Entsprechend pragmatisch die Lösung und das Erscheinungsbild des von den ca. 400 Studierenden bewohnten Gebäudes. Nordamerikas Stadtzentren sind durch die Silhouetten der Wolkenkratzer geprägt, der Holzbau ist in Canada ein traditionsreicher Baustoff. Dass man sich Know-how für eine Bauaufgabe, die diese zwei Aspekte kombiniert, ausgerechnet im buchstäblich auf der anderen Seite der Welt liegenden „Ländle“, holt, ist ein weiterer Beleg für die Spitzenpositionierung des Vorarlberger Holzbau-Ingenieursgeist auf dem Gebiet.