Finland’s tallest wooden building opens in Espoo

Finland’s tallest wooden building has been completed in Keilaniemi, Espoo, Yle reports. The 56-metre office building will serve as the headquarters of Metsä Group, and its carbon footprint is estimated to be half that of a comparable concrete building.

The building, known as Keilaniemen portti, stands beside the glass office buildings of Microsoft, Fortum and elevator company Kone. It has 13 floors and a roof terrace from which Tallinn can be seen in clear weather, according to lead architect Arndt Heinzmann of ARCO.

The long, narrow building has a distinctive sloping shape. Its ridge height is six metres greater than that of the previous record-holder, the 14-storey Lighthouse Joensuu.

The facade is made of spruce treated with a yellowish finish intended to resemble larch. The original plan was to use larch, but its availability was poor because of Russia’s war of aggression, Heinzmann said.

Environmental considerations were central to the design. In addition to extensive use of wood, the building contains low-carbon steel, recycled aluminium and textile carpets made from recycled materials. Heinzmann said these choices reduce its carbon footprint by 50 per cent compared with a similar concrete office building.

Most of the interior surfaces are also made of wood. Few surfaces have been painted, leaving the materials visible. The concrete walls of the lift shafts retain the marks left by the formwork.

“The idea was to use authentic materials: wood should look like wood, steel like steel and concrete like concrete,” Heinzmann said.

The building’s design was inspired by the idea of extending the green coastal zone from the Archipelago Sea up to the roof. Its sloping form and green roof reflect that concept. The roof contains stonecrop and plants from nearby shores, while solar panels have been installed at its highest point.

Keilaniemen portti is also one of Europe’s tallest wooden buildings. Heinzmann said wooden office buildings are not becoming more common in Finland, but he believes the project could set an example for future construction.

Fire safety regulations remain a limiting factor, he said. Because of the regulations, Keilaniemen portti was built as two separate buildings that are effectively attached and form what appears to be a single structure.

The building is owned by occupational pension insurance company Varma, which invested in wooden construction because there is demand for such office premises.

“Our aim is to support environmental issues. Tenants have also said they want to locate in modern and environmentally friendly properties,” said Sampsa Ratia, Varma’s investment director responsible for real estate.

According to Ratia, demand for the wooden building was several times greater than the available space. Varma intends to commission more wooden office buildings in the future and is considering several possible locations.

“The rental market has been challenging and polarised for several years. There are many lower-quality buildings standing empty, but new properties like this attract queues at the door,” Ratia said.

Metsä Group and CSC Finland will be the building’s two Finnish tenants. Metsä Group’s 600 employees will move from Tapiola to Keilaniemi during the autumn.

“Many of our own products have been used in the structures and in the exterior and interior walls. That made the project an important choice for us,” said Jussi Björman, Metsä Group’s research and development director.

Metsä Group is the first forestry-sector company in Keilaniemi, which is known especially for technology and energy companies. Björman said the location offered good views and could encourage the company to compete with other large Finnish businesses.