Sustainable high-rise residential buildings to be built in central Pudasjärvi from logs
Sweco’s structural designers are involved in designing the high-rise residential buildings made from logs, which will be completed in the centre of Pudasjärvi by Pudasjärven Vuokratalot Oy in autumn 2021. The main contractor of the project is Rakennusliike Lapti Oy.
“These are hybrid buildings whose load-bearing frame will be made from concrete elements and the external envelope, façade and some of the adjoining walls will be made from locally sourced logs,” says Sweco’s structural engineering specialist Marko Karkulehto.
The design of the nearly 9.5-million-euro project has paid special attention to moisture management and protecting the logs during construction. Data modelling was used to support the design process. “It has eased risk management and work supervision both in production and on site,” says Lapti’s project development manager for northern Finland Tapio Ronkainen.
The data model has also been a valuable tool for log manufacturer Kontiotuote. ”The hybrid model provided the initial data for further design of the openings in the logs and enabled us to transport data directly to the machine in our log factory,” says B2B Business Director Hanna Haipus from Kontiotuote.
Massive logs are ideal for large buildings
Traditionally, logs were used to build holiday homes and one-family houses, and in Finland, one in four detached houses is made from logs. Kontiotuote’s WoodHow has a reputation of being the best in the world, but Hirsihovi has still been a learning experience for everyone involved.
“It was our task to marry concrete and log structures as well as production boundary conditions to create a sensible and cost-efficient building,” Karkulehto says.
Acoustics proved one of the challenges, as noise has traditionally only been managed horizontally in log houses. In a high-rise residential building, noise may not travel between floors. “Creating new solutions was a matter of having the right attitude and required that all parties allocate time for product development,” Ronkainen emphasises.
”Together with construction professionals and structural engineers, we were able to create a success story!” Haipus says with a smile.
A healthy and ecological building material
In Finland’s log capital Pudasjärvi, log is the building material of choice. Pudasjärvi already has an impressive log campus that has attracted visitors from all over the world. The façade of Hirsihovi in Pudasjärvi is made of SmartLogs by Kontiotuote, which do not settle as they dry. They act as sufficient insulation on their own – even in the event of fire.
”According to building regulations, large logs can be used for any structures,” Haipus says. In addition to this, logs also have an excellent ability to bind and release moisture, which makes for high-quality indoor air. ”This makes logs a very attractive material for housing companies, as well.”
Log buildings also serve as carbon stock, which is why log construction is often associated with an ecological carbon handprint rather than a carbon footprint. ”Choosing logs is not a small, but a big action to take for the environment,” Haipus notes.
Sustainable production makes logs an even more eco-friendly construction material. The Kontiotuote log factory produces more energy than it consumes, because the residual resources of production, such as woodchips and sawdust, are utilised in local district heating production, for example. The carbon footprint of a log house will not increase even due to transportation. ”All of the logs are sourced from responsible forest owners within a roughly 100-kilometre radius,” Haipus says.
Picture: Linja Arkkitehdit Oy