Towers made of timber could herald a new environmentally friendly era of construction

[M II A II R II K]

Towers made of timber could herald a new environmentally friendly era of construction


Mar 28 2011

By Larry Richards and Avi Friedman

Read More: http://www.themarknews.com/articles/...-in-our-future

In architecture, engineering, and forestry sectors around the world, there is a mega-buzz about forthcoming high-rise towers made of wood. Imagine a 20, 30, or even 40-storey condominium or office tower that has timber structural-members and is clad in wood. The modernist preoccupation with high-carbon-footprint concrete and steel may soon take a back seat to the innovation of towers constructed of wood. The earliest ventures in this direction started in Japan a decade ago. But numerous projects are now also on the drawing boards in Austria, Norway, Australia, and Canada.

With encouragement and support from the British Columbia government and its forestry division, architect Michael Green of Vancouver-based McFarlane Green Biggar Architecture + Design, is moving fast with proposals for 20- to 30-storey, timber-constructed towers that are highly earthquake- and fire-resistant and hugely eco-friendly. A provincial study to be released later this month will evidently not only make a case for the feasibility and safety of wood-constructed towers, but will also heavily promote the economic benefits for British Columbia. B.C. is indeed moving ahead on these fronts, having recently changed its building code to allow six-storey wood-frame construction.

It is likely that research, development, and testing will soon lead to even more radical changes in the building codes for timber and timber-composite construction. (For example, although inherently more flammable than steel or concrete, if a timber member has sufficient size and mass it will burn slowly before structural failure.) Green is clearly leading the way into exciting architectural territory. However, the recent claim that Green is developing “the world’s first ‘timber skyscraper’” is off the mark. Nearly a decade ago, Tokyo architect Kazuhiro Ishii commenced research for a 30-storey timber tower in the city’s Akasaka district. He worked with testing laboratories for several years to prove the viability of the project in terms of earthquake resistance and fireproofing.

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[mhays]

A few days early?

[Roadcruiser1]

Yeah, and what would happen to the trees?. Would we chop more of them down. Especially since they produce oxygen which is our air.

[speedy1979]

Funny thing is I just watched towering inferno.

[aic4ever]

Originally Posted by Roadcruiser1

Yeah, and what would happen to the trees?. Would we chop more of them down. Especially since they produce oxygen which is our air.

Algaes produce something on the line of 70-80% of the world's oxygen.

[LeeWilson]

It's going to take a lot of work to convince people that wooden highrises are safe. Would you live on the 20th floor of a wooden apartment tower? Better hope there is no rot or termites.

[M II A II R II K]

Earthquake and fire resistant are pretty bold claims. Look at the precautions that went into Taipei 101 with it's thick concrete walls and earthquake considerations.

[emathias]

Originally Posted by Roadcruiser1

Yeah, and what would happen to the trees?. Would we chop more of them down. Especially since they produce oxygen which is our air.

Cut wood actually acts as a carbon sink, or bank, holding the carbon in reserve. Living trees are fairly carbon-neutral, except for what they absorb to grow.

Originally Posted by speedy1979

Funny thing is I just watched towering inferno.

Originally Posted by LeeWilson

It's going to take a lot of work to convince people that wooden highrises are safe. Would you live on the 20th floor of a wooden apartment tower? Better hope there is no rot or termites.

Yeah, I'm not sure I'd want to live in a building of double-digit stories made of wood.

Originally Posted by M II A II R II K

Earthquake and fire resistant are pretty bold claims. Look at the precautions that went into Taipei 101 with it's thick concrete walls and earthquake considerations.

Pagodas survive earthquakes fairly regularly. I think there are a lot of materials that can be assembled in earthquake-resistant ways, including wood. In fact, I think an earthquake might be the least of my worries in a tall wood structure.

[zilfondel]

Old news:

http://inhabitat.com/worlds-tallest-...ed-for-norway/

Shigeru Ban has also used wood and paper as a fire-rated structural material in many of his projects.

As far as earthquakes:

http://inhabitat.com/wooden-house-ca...e-earthquakes/

[scalziand]

Wood constructions earthquake resistance comes from its lightness, which reduces the forces generated during an earthquake. Wood is also very good at withstanding shock loads. As for fire resistance, keep in mind we're talking about large members here, not 2x4's. In a fire, large beams develop a relatively insulating layer of char about 2" deep, which helps protect the member from further burning.

[LeeWilson]

Originally Posted by emathias

Pagodas survive earthquakes fairly regularly. I think there are a lot of materials that can be assembled in earthquake-resistant ways, including wood. In fact, I think an earthquake might be the least of my worries in a tall wood structure.

Many Japanese pagodas have burned down, some rebuilt and burned down again, because of lightning. I suppose having a giant metal rod on top doesn't help. They're all grounded now though.

[Alpha]

None of the modern wood structures is taller than 70 metres. Nevertheless wooden structures with heights until 190 metres were realized ( from 1928 to 1935 nearly all radio towers in Germany were built of wood, the tallest, that stood from 1934 to 1945 in Mühlacker was 190 metres high), but higher objects may have structural and maintenance problem. The only of those wooden radio towers that still stands is that in Gliwice with 118 metres height.

[Canadian Mind]

Originally Posted by Roadcruiser1

Yeah, and what would happen to the trees?. Would we chop more of them down. Especially since they produce oxygen which is our air.

You need to get out of the city more appearently... For every human on earth there is around 10 000 trees.

[Roadcruiser1]

What I live in NYC.

[Chicago Shawn]

As someone who as witnessed the burning of 80-110 year old timber loft buildings, I firmly believe this is a bad idea. These structures burn for a very long time once a fire has a good start. The charring of the timbers holds hot embers that will retain heat for a long time. If the sprinklers do not not out a fire quickly, then the structure will be a total loss. If the exterior is non-combustible, i.e. brick; then the fire stays confined within the structure, while a wood exterior will be a different story. When a ~7 story timber loft burned in the South Loop a couple of years ago, the Chicago Fire Department was dumping water into burned structure for about a week.

Unless of course there is a new non-toxic method of fireproofing wood...

[M II A II R II K]

Oh yea and termites.

[Troubadour]

Definitely not a material for building monuments to the ages, but it could work for blandly designed, high-turnover structures that would be demolished and replaced a few decades later.

[Alpha]

But maintenance may be very expensive. As I know from wooden roller coaster structures each year extensive repair has to be made at the time when the park is closed.
And until which height would you say are wooden structures practicable?

[volguus zildrohar]

To quote a friend, "That's a lot of nails".

[M II A II R II K]

Maybe they should take the 3 little pigs into account.