The district of Vasastan in Stockholm showcases classic Nordic architecture from the late 19th and early 20th centuries. With its earth-toned residential houses, many Stockholmers consider the area typical of the inner city. The classic stone houses will soon have a new neighbour when the construction of Modellen 4, built with a wooden frame, is finalised.
The five-storey building will house 20 rental apartments and look similar to the surrounding ones, making it blend in smoothly with the environment of the district.
But there’s a small obstacle that needs to be overcome. Since Modellen 4 is built in a courtyard, most of the building materials need to get through a small portico. Project developer Christer Nilsson at Wallfast, one of the key figures behind the project, describes it as a “grand logistical exercise.”
“The size of the portico is approximately 2.5 x 3 metres, with a depth of about 15 metres. Luckily, we discovered that we could dig out the pathway running under the portico, which will give us a bit more space,” he says.
Despite the limited space available to squeeze through large amounts of timber and other building materials, Christer appears calm as he discusses the challenge.
“Everything is delivered to the street outside by truck. From there, the construction materials are loaded onto battery-driven tracked carriers that take them through the portico,” he says.
But that’s not the only thing that makes the building of Modellen 4 an exercise in construction craftsmanship. A crane on the street will lift another crane over the rooftops of the surrounding houses and place it in the courtyard. One crane lifting another might sound like a paradox, but in this case, it makes perfect sense.
“Once the crane has been placed in the courtyard, we’ll be able to lift the material from the tracked carriers and start building the timber frame. Having a crane standing on the street throughout the entire process would not only hinder traffic but also pose a security risk. Constantly lifting material over rooftops can be dangerous,” says Christer.
Given that the surrounding houses were built in the early 1900s, the construction team has to ensure minimal disturbance for the nearby neighbouring houses while also treating the portico carefully.
“We’ve covered the inside of the portico with planks to protect it during the shipments of materials. What’s also important is that we keep the neighbours informed about the different stages of the building process,” says Christer.
In Sweden, building with wood is a longstanding tradition. However, it’s only recently that multistorey timber-framed houses have risen in popularity. The structure of Modellen 4 will rely largely on cross-laminated timber, which has many advantages when compared with other types of building material.
“There are many reasons why timber is such a great material. It’s environmentally friendly as it captures carbon dioxide and it’s easier to handle compared with concrete for instance. For this project, getting concrete elements through the portico would have been almost impossible,” says Christer.
Christer believes that the rapidly growing trend of building multi-family houses in wood is set to continue and develop in even more efficient ways.
“When building at great heights, there’s obviously a point in using solid wood because it carries weight better. And I think we’ll find ways to become even more efficient by building with less wood. It’s unnecessary to use more wood than you need,” he says.
The first residents are expected to move in, in late August, 2024. Christer and the rest of the team have a lot of work ahead of them, but with determination and skill, they are ready to meet the challenges.
“Planning is key, and we have the right people with both the knowledge and the experience to help us build this,” says Christer.
DID YOU KNOW
1,200 trees – that´s about what it takes to build an average apartment house.
Wood is a renewable resource – the annual growth in Swedish forests is around 100 million cubic metres. That’s enough to build some 84,000 apartment buildings.
Buildings with wooden frames account for some 20% of constructions today.