Isn't it good? Norwegian wood - taller wood structures

Wood Focus magazine
,
21 Apr 2010
An illustration of the Manned Barents building

Skyscrapers are nothing new – but what about one made of wood? It does not exist yet, but Norwegian architect Reiulf Ramstad has plans for a 70m tall wooden building. If it can be funded and built, the 17-storey Barents Secretariat in Kirkenes, Norway (pictured left) would become the world’s tallest inhabited wooden structure.

For some time, that record was held by a building just a few hours away from Kirkenes – across the Russian border in Arkhangelsk. But the ‘Sutyagin House’, designed and built by Nikolai Sutyagin, was demolished after it was declared unsafe by a local court.

The Barents Secretariat is responsible for forging closer relations between Norway and its neighbour Russia. The proposed ‘signature building’ would act as a ‘lighthouse for the development of the Barents region’, says the Secretariat, and would include a library and a theatre.

Ramstad believes that making such a high rise structure in wood might also be a step towards more sustainable building methods. He says that the building industry is a major generator of CO2, and hopes that his design will help to push construction towards more sustainable techniques.

‘We have a tradition of wooden architecture in Norway, for everything from houses to churches,’ says Ramstad. ‘I think this way of building will become more common, as it shows sustainable thinking. Even the lift shaft is made of wood. ‘We want to see if it’s possible to make large buildings using this type of material,’ he says.

Tall order

Ramstad plans to construct the building from laminated wood. These beams are made from several layers of planed wood, which are joined together under high pressure, using glue or wooden bolts. Because of the way the beams are prepared and treated, they offer superior strength and suitable fire retardancy.

The two main suppliers of these beams (also known as Glulam) are Holz of Austria (which joins the layers together with wooden bolts), and Moelven of Norway (which uses glue). Both make the beams from spruce, though Holz can also supply them in larch.

There are a number of challenges that Ramstad would face in the final building – not least the need to ensure that the underlying wooden structure is strong enough.

‘For tall buildings you need a very rigid structure,’ he says. ‘You also need control of the material’s static properties. If you use standard steel, it’s certified – but that’s not the case for these materials.’

At the same time, steel beams can be made to span just about any distance. Wooden beams, however, cannot do this, and so must be joined together.

Ramstad is not alone in designing such a construction. UK architects Waugh Thistleton helped to create a nine-storey, 30m high wooden apartment block in London, which was completed in 2009. The building – known as Murray Grove Tower or ‘Stadthaus’ – uses cross-laminated timber panels for the loading structure. The wall panels are 4.5 inches thick, the floor panels six inches thick. As well as reduced environmental impact, the building was built around 40% faster than a traditional concrete structure.

Ramstad has plenty of experience designing buildings with wooden loading structures – the Romsdals Museum on Norway’s mountainous west coast should be finished by 2011.

‘We’ve drawn up detailed plans and calculated everything,’ he says. ‘It’s designed as an “experience of nature” – the Barents building is more like an urban building.’

The outer cladding – also wood – protects the internal structure from damp. Re-used and recycled material is used for elements such as heat insulation. But Ramstad admits that he will have to resort to other materials for some of the critical structures of the Barents building.

‘You can’t rely completely on wood,’ he says. ‘Some of the joints are made out of steel.’

The only other major non-wooden elements are the concrete foundations – which are needed to resist damp – and the windows.

And if scaling up from the 4,000 square metres museum to the proposed 100,000 square metres Barents building seems a challenge, he insists that it must be done. ‘It’s not just about the size of the building,’ he says. ‘It’s also about the concept.’

Dead wood

If laminated wood is the future, this is definitely the past. Scientists at the Norwegian University of Science and Technology last year found perfectly preserved trees – in the humid southwest of Norway – that died over 500 years ago.

‘This is much older than we expected,’ says Terje Thun, Associate Professor at the university’s Museum of Natural History and Archaeology. ‘They have kept from decomposing for several centuries in this humid climate. This is quite extraordinary.’

He says the ‘mummified’ trees have survived so long because when pine trees die they secrete a lot of resin. This deters the microorganisms that cause decomposition. ‘Many of the trunks we dated seeded in the early 1200s and lived for more than 100 years at the time of the Black Death – around 1350,’ he says. ‘That means that the dead wood has “survived” in nature for more than 800 years without breaking down.’ 

Growing up – the world’s tallest wooden structures

1 Yingxian Pagoda, Shanxi Province, China (67m/220ft)

The pagoda (pictured right), part of the Fogong Temple, was built in 1056 and is reputed to have survived seven earthquakes.

2 Tillamook Airship Hangar, Oregon, USA (58.5m/192ft)

Built in 1942, the structure uses an all-wood 3D truss to free-span over seven acres of floor space. Many similar hangars were built due to a wartime shortage of steel.

3 Gliwice Radio Tower, Poland (118m/387ft)

Technically the tallest wooden structure in the world, it has stood since 1935 and is known locally as the ‘Silesian Eiffel Tower’. German troops staged a fake ‘Polish’ attack on it in 1939, and later used the incident to justify the invasion of Poland.

4 Barsana Monastery, Romania (57m/187ft)

This church was built in 1720 from thick beams of oak set on stone foundations. No nails were used in its construction.

5 5 Murray Grove Tower, London (30m/98ft)

While nowhere near as tall as some other structures, this nine-storey building is more modern and practical. It is made from cross-laminated panels – the same method that would be used for the Barents building. 

Further information

www.barents.no

www.reiulframstadarkiteker.no