Spreading like wildfire: Why wooden skyscrapers are springing up across the world

Photos: Timber and bamboo -- wooden buildings are branching out

Wooden skyscrapers – The Wood Innovation and Design Center (WIDC) is located in the province of British Columbia in Canada.

Story highlights

• New super strength products such as engineered bamboo are making timber a more popular building material
• Experts say wooden buildings have a positive psychological effect on people

Wood is being billed as the answer to creating greener cities -- lightweight and sustainable, it is even said to be more fire resistant than steel.

The newest addition to the timber trend is a proposed 19-storey structure that will be built in the Swedish city of                                                                       Skelleftea.

Wooden skyscrapers – The building is a hub for wooden design education and research.

Designed by architecture firm White Arkitekter, it was the winning submission in a competition to design a cultural center and hotel in the Swedish city.

Wooden skyscrapers – The "Sida Vid Sida" ("side by side") building is a proposed project by Swedish architects White Arkitekter.

The "Sida vid Sida" -- its name translated to side by side" -- submission was praised for paying tribute to the city's rich local timber industry, and the multiple design benefits attributed to wood as a building material.

Once complete, the 19-storey structure is expected to become the tallest wooden building in the Nordic countries.

 Wooden skyscrapers – CRG Architects proposed a skyscraper made entirely of bamboo at the World Architecture Festival in 2015.

Spreading like wildfire

An explosion of timber towers, either built or proposed, has gripped the architecture world over the past five years, every one seemingly a recorder holder in some respect.

In 2012, the 10-story, 104-feet-high Forte residential block was erected overlooking Melbourne's Victoria Harbour.

It was the world's tallest timber building until The Treet in Central Bergen, Norway, stole that title in 2014, with an extra four stories.

Wooden skyscrapers – At 80 stories high, it would be London's first wooden skyscraper, and another addition to the growing trend for structures made entirely of timber.

 Last year, the Cube, a 109-feet-high apartment block in London's Shoreditch, became "the tallest cross-laminated timber structure in Europe," according to its developers.

In Canada, work has begun on the descriptively named Tall Wood Building, which will provide student digs at the University of British Columbia.

At 174 feet and 18 stories tall, it was set to be the world's tallest building, until the Oakwood Tower came along.

The Oakwood Tower is a proposed joint project by PLP Architecture and Cambridge University's Department of Architecture. It's an experiment in pushing the frontiers of building with wood, and is part of a growing movement to build in timber.

The 80-story tower, if given the green light for construction, will be made of timber -- making it London's first wooden skyscraper and the tallest wooden structure in the world.

At 1,000 feet tall, it will only be overshadowed in London by The Shard.

 Wooden skyscrapers – Oakwood Tower is a proposed structure by PLP Architecture and Cambridge University's Department of Architecture.

Branching out

New types of ultra-strong timber are partly driving the trend.

"There's a whole bunch of new materials made out of wood that are structurally able to build big buildings," says Dr. Michael Ramage, of the Center for Natural Material Innovation at Cambridge University.

Cross-laminated timber, for example, sees thin layers of wood placed across one another at right angles, and laminated with fire-resistant glue to create a stronger weave.

But it's bamboo -- a material that has been used in Asian construction for centuries -- that most interests Ramage.

With a five-times higher growth rate than wood, but similar mechanical properties, there are 31.4 million hectares of bamboo worldwide, according to the Food and Agricultural Organization.

"We're working on engineered bamboo," says Ramage. "We can take the walls of bamboo tubes, cut them up into rectangles and glue them into big slabs.

"You get large pieces of what looks like lumber. But it's stronger than timber."

Kevin Flanagan, a partner at PLP architects, adds that in the future he can imagine the industry genetically modifying wood to make it even more conducive to high-rise construction.

Wooden skyscrapers – In Bali, the 18-home Green Village is constructed almost entirely of bamboo.

London's burning?

Obviously, when it comes to wooden buildings, there's one burning question.

Are timber skyscrapers a fire hazard?

Ramage says Oakwood Tower -- which will be an extension of the Barbican Center in Central London -- will exceed the fire standards of regular steel and concrete buildings.

His center has been awarded £250,000 ($353,785) from the Engineering Physical Sciences Research Council in the UK to research timber construction techniques, such as fire proofing.

"There is a huge perception problem," says Ramage. "Timber doesn't burn in the way the public imagines.

"The great fires of London and Chicago were both sparked by very small pieces of wood. Very big pieces of wood are quite hard to set on fire -- they aren't kindling material."

Wood, he says, burns predictably. Therefore, fire engineers can calculate how large a block of wood is needed to provide a protective layer to sustain a building for a certain period of time.

"All buildings over a certain size need to have sprinklers and active fire suppression systems -- irrelevant of whether it's wood, concrete or steel," he adds.

A series of blazes at Dubai skyscrapers in recent years have highlighted that it isn't just timber buildings at risk of catching fire.

 Wooden skyscrapers – Bamboo was recently recognized by the United Nations as a green building material that can help combat climate change.

Wooden skyscrapers – The Forte in Melbourne was completed in 2012, and is a 10-story structure built entirely of wood.

 Does wood make us happier?

According to Flanagan, wooden buildings have a positive psychological effect on people.

"People tend to feel relaxed around wooden buildings," says Flanagan. "People associate wood with green spaces, they have an affinity to it. There would be a real benefit to introducing wooden structures to the cities where people live."

In 2009, the Austrian Joanneum Research Institute compared four classrooms: two with timber flooring, ceilings and cupboards, and two fitted with linoleum floors, plasterboard walls and chipboard cupboards.

Children working in the timber classrooms, researchers found, were more relaxed, displaying lower heart rates.

Wooden skyscrapers – For two years, the 104-foot tall structure was the tallest wooden building in the world.

Wooden skyscrapers – Treet was completed in 2014, and is 14 stories tall.

Wooden skyscrapers – That title was soon taken by the Treet in Norway.

Wooden skyscrapers – The building is expected to be completed in 2019

Aren't we meant to be saving the rainforest?

Yes. According to the World Wildlife Organization, up to 58,000 square miles of forest are lost each year -- that's equivalent to 48 football fields every minute.

But Ramage explains that Oakwood Towers, if approved, would be built from "white wood" -- that is, crops grown over a 40-year-period specifically for construction purposes.

"Russia has huge timber reserves, largely because we're finally using less paper," he explains.

In fact, using wood could be more sustainable. Ramage says wood is, on average, four times lighter than concrete, so transporting it uses less energy.

Furthermore, timber buildings are increasingly being assembled in a factory, and then craned into position and fixed together on site -- like an Ikea-style skyscraper that can "self-assemble".

"This has huge time and financial savings implications," says Flanagan..

Wooden skyscrapers – The proposed design won an architecture competition in the city of Skelleftea. There were 55 entries from 10 countries.

Wooden skyscrapers – The design was selected for its use of wood as a building material, as it pays tribute to Skelletea's rich local timber industry.

Wooden skyscrapers – "This is the future. It's pure architecture ... to breathe fresh air and touch nature, that's everything," says architect Defit Wijaya.

Won't wood rot?

From the magnificent Tudor timber arches of Westminster Hall in London to the wooden rooftops of the Forbidden City in Beijing, wood has been used to construct some of the world's most beautiful, iconic buildings.

And they haven't fallen victim to rot.

"We know from a very long history of building in wood it can last -- we have 600, 700-year-old buildings in the UK which are fine," says Ramage. "The one constant they have is that they have all been well looked after."