Flat-packed cities: Wooden skyscrapers sprout over concrete concerns

By Rina Chandran

For more than a century, countries have raced to build the world's tallest buildings with concrete and steel. Now, a quiet contest in constructing tall wooden buildings, from Amsterdam to Tokyo, underlines growing environmental concerns over concrete.

With rapid advances in engineered wood, and authorities relaxing building codes, wooden structures are sprouting across Europe, Canada, the United States, and in the Asia Pacific region.

At 73 meters, Amsterdam's Haut building is said to be the world's tallest wooden residential tower.

Vancouver plans a 40-story building it says will be the world's tallest, a title also claimed by Sumitomo Forestry's 350-meter skyscraper in Tokyo.

"The interest is definitely being driven by environmental concerns - the amount of damage we're doing with concrete is unbelievable," said John Hardy, a sustainability expert in Bali, Indonesia.

"Bamboo and wood are carbon sequestering materials. So the other advantage of building with them is that you will look better to your children and grandchildren," he said.

Construction of office towers, bridges, airports and highways is booming in developing nations across the world.

The manufacture of steel, concrete and brick accounts for about 16% of global fossil-fuel consumption - and up to 30% when transport and assembly of the materials is considered, according to the Yale School of Forestry & Environmental Studies.

Concrete is also blamed for rampant sand mining, which has damaged the environment and hurt livelihoods in Southeast Asia.

In addition, an abundance of concrete has worsened urban flooding, and made cities hotter, environmentalists say.

In contrast, wood requires fewer fossil fuels to transport and assemble, and also effectively stores large amounts of carbon - trapped as the trees grew - for years, helping curb emissions, said Andy Buchanan, professor of timber design at the University of Canterbury in New Zealand.

Each cubic meter of timber used in construction stores a carbon equivalent of over 900 kilograms (2,000 pounds) of CO2 emissions, meaning a reduction of 135 kg-360 kg of CO2 emissions per square meter of floor area, said Buchanan.

Innovations such as glue-laminated timber, laminated veneer lumber, and cross laminated timber - strips of wood glued together to make beams - are creating more uses for structural timber in residential and commercial projects, he said.

Structural timber is much lighter than concrete, cuts risks in earthquakes and can "create far more attractive interiors", he said.

"As tall timber buildings become more popular, the perceived disadvantages - fire safety, durability and the supply chain - are being overcome with good design, excellent case study buildings, and technology for engineered-wood products."

Examples are easy to find, from London's nine-story residential Stadthaus to Melbourne's 10-story Forte apartment building.

A 54-meter wooden building in Vancouver that was thought to be the world's tallest was quickly overtaken by an 85-meter tower in Norway.

Amsterdam's 73-meter Haut will begin handing over its 55 apartments from 2021. Vancouver's planned 40-story building will include 200 flats, while the 70-story Tokyo tower is slated to be completed by 2041.

"New technology, combined with accurate computer fabrication, now enables a wooden building to be assembled incredibly fast, like a giant piece of flat-packed furniture," said Andrew Lawrence, a timber specialist at Arup, which designed Haut.

"Wood is ideally suited for lower rise buildings, but it is really exciting that engineers and architects worldwide are experimenting with the use of wood for taller structures," he said.

Such buildings are particularly suited to cities, where buildings are constantly being adapted and refurbished for new uses, said Eleena Jamil, a Malaysian architect who has designed residential and commercial structures with bamboo and wood.

"Cities go through fast-paced changes. The advantage of using bamboo and timber is that they are easy to dismantle, reuse and adapt, compared to concrete," she said.

But with excessive logging and deforestation already a problem in many Southeast Asian countries, it is important to balance demand for wood with "tighter regulations and more efficient management of forests," she cautioned.

Under pressure to act on a material that produces 7% of the world's carbon dioxide emissions, cement manufacturers also have been experimenting with lower-carbon concrete.

Authorities in several U.S. states are exploring the use of carbon-injected concrete that will use less cement while trapping carbon emissions.

Meanwhile, policy initiatives are hastening the move to wood from steel and concrete.

In New Zealand's Christchurch, where authorities have encouraged a more environment-friendly approach after a 2011 earthquake that flattened much of the central business district, timber is a favored material.

The city, which creates about 600,000 square meters of new buildings each year, has the opportunity to store the equivalent of 30,000-200,000 tons of CO2 emissions per year if all new buildings were made of wood, said Buchanan.

Regions including British Columbia and Tasmania have adopted a "wood first" or "wood encouragement" policy that requires building designers to show that they have considered wood as an option.

Japan has a law to promote use of wood in public materials.

Such policies are "probably the most effective to encourage greater use of wood as a construction material, especially if supported through a carbon encouragement grant", Buchanan said.

But the decision to use wood must be a considered one, said Amy Chow, a designer in Hong Kong who curated a show on wood, paper and bamboo.

"You can't start off saying: let's build this out of wood," she said.

"It has to be the culmination of a process to determine what works best in that context, what is most sustainable, cost effective and efficient," she said.

© Thomson Reuters Foundation

©2019 GPlusMedia Inc.

Login to comment

Although it's better than concrete, I wouldn't really describe their properties as an "advantage," just slightly less of a burden. Once wood and bamboo start becoming used in greater quantities, I'm sure it will result in other negative effects on the environment. Urbanization and environmental conservation are not really compatible.

2 ( +2 / -0 )

Timber and bamboo buildings won't contribute to the heat islands in cities, unlike concrete and glass that rack up the temperature.

3 ( +3 / -0 )

Interesting. I like it.

1 ( +1 / -0 )

I am amazed at the genius of those with high IQ status. Wish I was part of the team. Actually I am, but do not brag. Goemen ne

-4 ( +0 / -4 )

"The city, which creates about 600,000 square meters of new buildings each year, has the opportunity to store the equivalent of 30,000-200,000 tons of CO2 emissions per year if all new buildings were made of wood, said Buchanan."

Actually, no. Once felled, the ability of the trees to fix carbon is, of course, gone. If not felled for building material or any other use, these trees would store even more carbon over time. The advantage as a building material is that trees and bamboo can be replanted. However, it takes decades before any tree is very useful as a store of carbon or as building material.

-1 ( +0 / -1 )

I just pictured myself lounging about in the penthouse apartment of a high rise wooden building when a smoker on the first floor set the building aflame. It was not a pleasant picture.

0 ( +1 / -1 )

Login to leave a comment

Facebook users

Use your Facebook account to login or register with JapanToday. By doing so, you will also receive an email inviting you to receive our news alerts.

Facebook Connect

Login with your JapanToday account

User registration

Articles, Offers & Useful Resources

A mix of what's trending on our other sites