Arctic-Tecture

20 July 2008 (Last Updated July 20th, 2008 18:30)

Eve Kushner explores how buildings are being equipped to endure the challenging climate of Scandinavia.

Arctic-Tecture

You might assume there would be straightforward rules for building in an extreme climate: keep the heat in and the cold out. And you might assume that one cold, northern country is pretty much like the next. But it's not nearly that simple.

There is enormous climatic variation across Scandinavia. Seasonal changes create two very different worlds: a landscape with endless summer light and a wintry environment in which the sun appears briefly, if at all.

From Iceland's reliance on hot springs and Norway's use of ground heat to Denmark's harnessing of the wind, as well as Norway's wood, Denmark's clay and Iceland's stone – the countries draw on very different raw materials.

The choice of raw materials has shaped not only the vernacular architecture but also each culture's attitudes towards conservation and energy efficiency.

EXTERIOR MATERIALS

Norway and Sweden have abundant supplies of wood. "Relatively cheap and plentiful, wood seems an obvious building material that one uses reflexively and even mindlessly," says architect Einar Jarmund of Oslo-based Jarmund / Vigsnaes Architects.

Wood creates a warm feeling, so Icelanders particularly appreciate it. Because trees can't grow tall in their climate, Icelanders import any wood they use. They also tried importing the idea of wooden houses from Norway and Sweden. But under siege from Icelandic winds, such houses became untenable and eventually acquired corrugated steel cladding.

For a more durable, exotic and expensive cladding choice, copper is one possibility. Traditionally used for high-quality roofs, copper has been key to the success of the Svalbard Science Centre in northernmost Norway. In 2005, Jarmund's firm finished an expansion of the existing science centre, cladding all exteriors in copper.

"For a more durable, exotic and expensive cladding choice, copper is one possibility."

"It turns out that copper is a very suitable cladding in such a climate," says Jarmund. People release quite a lot of humidity (about two litres of perspiration each, every day), which poses challenges when it's 25°C inside a building, and -25°C as well as extremely dry outdoors. These temperature and humidity differentials create problems such as condensation on windows. But tiny amounts of air can leak out through standing seams in copper cladding, enabling the building to breathe.

Jarmund also resolved the humidity problem by installing a layer below the copper cladding. This sub-layer works the same way as a Gore-Tex raincoat, which keeps people dry but still allows humidity to evaporate.

Architect John Lassen of Schmidt Hammer Lassen in Aarhus, Denmark, also chose a metallic cladding for a project in Alta, northern Norway. After construction starts in November, titanium will clad the Cathedral of the Northern Lights, co-designed with LINK Signatur AS of Norway.

Alta offers a front-seat view of the Northern Lights, and Lassen wondered whether it was possible to represent them in architecture. To complement wavy auroral shapes, he has created an ethereal, vaporous, spiralling form for the church. Copper lacks sufficient reflective sheen, so Lassen chose titanium, which will serve as a blurry mirror.

SHAPE OF THE BUILDING

Lassen and Jarmund emphasise that wind and snow will blow around circular shapes such as the Alta church, whereas winds tend to batter rectilinear buildings and pile snow against their façades.

The shape of a building bears a direct connection to heat conservation, as well. A long, thin building has much more surface area than a blockier structure. To prevent heat loss through the skin, one should minimise the surface area, says Jarmund. But it's a trade-off, he acknowledges – a long, slender building admits more daylight, thus reducing the energy used for electric lighting.

INSULATION

At Svalbard, Jarmund used 25cm of insulation in the walls, with quite a bit more in the roof. But the wall isn't solid. To protect against moisture, he left a 5cm cavity behind the cladding, rather than putting the cladding directly onto the sheathing. Widely used in Norway, this type of 'rain screen' wall enables wet cladding to dry, which helps the cladding last much longer.

"Titanium will clad the Cathedral of the Northern Lights, co-designed with LINK Signatur AS of Norway."

Meanwhile, in Iceland, concrete is a widely used building material. Interior insulation is cheaper and easier than exterior insulation but isn't the most effective. Exterior insulation has become a common Icelandic practice, according to Pálmar Kristmundsson of the Reykjavik firm PK Arkitektar. He used this technique in his Kentucky Fried Chicken franchise in Keflavík, adding exterior insulation to the concrete structure and then cladding the building in tiles.

WINDOW ISSUES

In Oslo (where glass office buildings overheat in the summer) and in Denmark (where architects always look for the light), fenestration issues are similar to those in the rest of Europe. But in the extreme north, windows pose complications, leaking great amounts of interior heat while admitting only negligible amounts of warmth from the sun.

Windows also need to go in just the right location. Architects avoid placing windows down low. Skylights prove a very effective mode of daylighting, say Lassen and Jarmund, because a window in a horizontal surface admits much more light than a window in a vertical surface.

THE LIGHT FANTASTIC

According to Thorbjörn Laike of Lund University, the most important thing is to have daylighting, daylight from the right direction. From the northern side, especially higher up in the window, you can get general daylight without glare. Before electric light, daylight architecture was quite widespread, but then it was forgotten.

But of course that's not enough, because if you go extremely far north, you don't have daylight during the wintertime. Then you need to rely on electric lighting. The reflection from the walls is also important for getting good light in the environment. You should have a wall colour that reflects light in a pleasant way. Then you could use artificial lighting as a wall wash.

Research has shown that the right kind of lighting could lessen seasonal affective disorder (SAD). SAD is when your well-being is lower, you're not interested in seeing other people, you have problems sleeping, you're fatigued and so on. In one study we compared about 1,000 people, some working close to the equator in Saudi Arabia and northern Argentina, and some in England and Sweden. We saw that if you felt your office environment was light, you had fewer problems than if you felt your environment was dark.

"Wind and snow will blow around circular shapes such as the Alta church."

People in northern parts want a warmer light colour temperature – about 3,000K (Kelvin). Colour temperature is the colour of the light you see. It has nothing to do with heat. When you have a fluorescent tube, you could have it very cold – a bluish one, which is 5,500K. If you have it more yellow, you have 3,000K. When you see this kind of light, you feel that the environment is cosier and more enclosed.

GLOBAL WARMING

You might think that as the world heats up, Scandinavian architects would relax their rigorous climatic responses. But in fact, people in these northern countries are already noticing rising sea levels, melting glaciers and less snow. Whereas people all over the world focus on harnessing or conserving energy and taking other measures to forestall global warming, some architects are one step ahead and are responding to the changes already at hand.

Lassen and his colleagues spend considerable amounts of time discussing ways of responding to rising sea levels. He and other Danish architects often elevate structures by putting them on concrete piers. Near the sea in Denmark, he says, you build 1m higher than a decade ago. Foreseeing a grim future, the Danish government has taken a keen interest in this issue. The government has invested a lot in windmill production, so Denmark now produces vast amounts of wind power.

Over in Iceland, architects think about insulating well, dressing buildings in a 'climatic coat' to keep out the cold, choosing materials that one can reuse and designing to use less energy.

However, Iceland benefits from abundant hot springs, waterfalls and steam, giving most Icelanders access to cheap heat and electricity and thereby changing the whole discussion. Having a profusion of cheap geothermal energy makes Icelandic architects more relaxed about energy conservation. Energy regulations here are not as strict as in other Scandinavian countries, and Icelanders aren't thinking deeply about global warming.

Basements in the old centre of Reykjavik regularly flood at high tide, and a rising sea level greatly threatens this area of the low-lying capital. Nevertheless, says PK Arkitektar's Kristmundsson, architects are building in that area of the city without accounting for future climatic changes.

"A long, slender building admits more daylight, thus reducing the energy used for electric lighting."

Norwegian attitudes couldn't be more different.

Owing to strict Norwegian energy codes (which mandate a high level of insulation, for instance) and an inherent cultural tilt toward sustainability, Norway has built conservatively for years. Ground source heat pumps or geothermal systems pick up heat from water circulating through pipes deep in the ground, thereby providing a cheap and readily available source of energy.

For every kilowatt that goes to extract that heat, you get three or four kilowatts in return. But this isn't good enough, says Jarmund: "I think in 50 years, we will think about the 20th century, and we'll be shocked that you could actually build buildings that needed energy."

He adds: "We all have to adapt to these issues. We should have adapted many years ago." Energy conservation requires increased attention to the relationship between the inside and outside of a building. "This is probably one of the biggest challenges architecture has ever encountered."