WINNIPEG, MB, May 29, 2013/
Troy Media/ – In 1885, the Home Insurance
Building in Chicago opened its doors. At 10 stories, it was the world’s
first skyscraper, and the first building to use a steel frame in its
construction. Since then, the use of steel and concrete has
proliferated, allowing North American architects to build taller and
ever more impressive multi-storey structures.
While these two materials dominate modern high-rise construction,
both come with serious environmental concerns. Three and 5 per cent of
the world’s carbon emissions are generated in steel and concrete
production, respectively. As such, a growing number of architects argue
we must find a new material to meet building needs in the 21st century,
and they believe they have the perfect alternative: wood.
Of course, wood is not actually a new product; humans have been using
lumber in construction for thousands of years. Even in 2013, almost 80
per cent of Canadians live in wood homes. Because of very legitimate
concerns of rot and fire, however, back at the turn of the last century
building codes restricted wood structures to no more than four stories —
and these regulations have remained on the books since.
Today though, the technology exists to build timber-framed high-rises
stretching up to 30 stories tall. Proponents point out such wooden
skyscrapers would not only be cheaper than their steel and concrete
counterparts, but sustainably-forested timber is also far more
environmentally friendly than conventional construction materials.
According to Vancouver architect Michael Green, there is enough wood
grown every 13 minutes on this continent to make a 20-floor building
and, unlike producing steel or concrete which emits greenhouse gases,
using wood in construction actually sequesters carbon.
In fact, due to the effects of climate change and insect infestation,
there is a growing population of dead trees in North America. Instead
of leaving these to decompose and release carbon dioxide into the
atmosphere, advocates argue this bountiful resource could easily be
harvested, treated, and put to use building up cities.
In 2009, the first modern wood high-rise was built in London,
England. The nine-storey condominium tower proved hugely popular, with
all 29 of its units selling out within an hour. A seven-floor building
then went up in Sweden, and Melbourne, Australia, currently boasts the
world’s tallest modern wood building, a 10-storey skyscraper. The
apartment block will soon be eclipsed though, as Vancouver, B.C., is
reviewing a proposal for a 16- to 20-floor wooden tower, and Sweden has
already approved a skyscraper of 30 stories.
Certainly, many people may be skeptical of the feasibility of wood
cities, fearing the lumber will easily catch fire. Yet, as Geoff Triggs,
an expert with LMDG Building Code Consultants points out, wood
high-rise construction does not use small two-by-fours. Rather,
super-compressed mass timber — engineered wood layered together with
adhesives or fasteners — is used to make huge panels 64 feet long and 12
feet wide. The compressed lumber has proven to be as strong as concrete
but much lighter, which improves a building’s structural integrity.
Moreover, these panels can be made off-site and then installed,
dramatically reducing construction time as there is no waiting for
poured concrete to dry.
Most importantly, the compression process creates dense wood blocks
that, much like a big, fat tree stump in a fireplace, are very difficult
to burn. When a fire does catch, it moves slowly and behaves
predictably, allowing for uniform safety measures to be put in place. A
2012 study published by Surrey, B.C.’s, fire chief noted that modern
fire protection systems such as sprinklers (that did not exist when most
regulations regarding wood building construction were adopted) “more
than mitigate” the risks of building tall timber structures.
In the next 20 years, three billion people will be moving to cities
around the world, and high-rises will be a critical part of their
housing mix. According to wood advocates, modern safety measures and
technology mean this ancient material can be an asset in building these
new skyscrapers. The biggest hurdle will likely be convincing the public
that wood is just as safe as conventional concrete and steel — but as
more wooden buildings go up, engineers will be able to provide hard
evidence as to whether or not they are more dangerous than conventional
structures.
It would be nice if they do prove to be secure; beyond the
considerable environmental benefits, wood could add an appealing warmth
and dimension to the skyline that is impossible to achieve with drab
concrete and steel. If nothing else, it would give new meaning to the
phrase ‘city of trees’.
Troy Media Municipal Affairs columnist Benjamin Gillies is a
political economy graduate from the University of Manitoba, where he
focused on urban development and energy policy. He works as a consultant
in Winnipeg.
