From single-family home construction to more challenging landmark sites

Kokkonen says that wood is a versatile material and pre-prepared modular elements shorten the worksite time. Sweco was involved in the first CLT apartment building projects, developing the design and use of the material. Sweco’s experience with public wood construction sites in Finland is extensive, ranging from schools and day care centres to sports construction and libraries.

“Our strength lies in the fact that we have around 60 wood structure designers who work solely on wood and hybrid projects every day. Our expertise ranges from single-family homes all the way to the most challenging of landmarks,” Kokkonen says.

One such landmark site is the new wooden Mansikkala School in Imatra, which received an honourable mention in the Finnish Wood Award 2020 competition. Pupils got to start a new school year at the school this autumn. Nurmi says that commissioning the school was challenging from a pedagogical standpoint, as pupils were transferred from several small schools to a new teaching system and an open learning environment.

The cosiness of the wooden building was a big help amidst all the changes. Nurmi describes the wood-decked facilities as soft-looking and the wood material as having a calming effect on the soundscape.

“We have received positive feedback saying that the school is comfortable to be in. The acoustics are great. Public buildings are rarely praised as works of art, but the school really is a fine building inside and out,” Nurmi comments.

Public wood construction developing in leaps and bounds

Tähtinen praises the boldness with which municipalities have undertaken projects like the Mansikkala school. Nurmi says that during the Mansikkala school project alone, attitudes towards wood construction took a clearly positive turn. In three years, public wood construction has taken a giant leap forward.

In Imatra, wood construction continues, and Sweco is involved in creating a concept plan for a carbon-neutral sports building. The work currently focuses on researching how sports construction can be implemented with different wood product concepts while taking overall ecologicality into account.

“We must tip our hat to Sweco for their competence and expertise. They have taken innovative steps in planning and developing wood construction. Pioneers are exactly what the concept needs,” Nurmi says.

Tähtinen and Kokkonen say that the projects have generated valuable material experience supported by resources, software and good networks with clients, commissioners and prefabricated element suppliers.

The Hippos day care centre is the first public wood building built from CLT elements in Tampere, and Sweco meticulously surveyed different implementation alternatives with the client. The client and the contractor had not worked with CLT elements before. Sweco is already working on a new project with them in Tampere, the wooden Isokuusi day care centre and school.

“Sweco was required to provide strong instruction regarding the preconditions and characteristics of wood construction in structural engineering and architectural design. We instructed both the client and the contractor in equal measure,” Kokkonen says.

Hybrid construction taking the entire construction industry forward

A feature shared by the Hippos day care centre and the Mansikkala school is adaptability, which is characteristic of day care centre construction. In Mansikkala, adaptability was implemented with a module division.

Because wood construction is not as standardised as concrete and steel construction, the designer must be familiar not only with element suppliers and manufacturing and installation methods, but with other materials and material interfaces as well.

“The designers must know how different materials behave with one another. Sweco has this expertise at both the individual designer level and the company level in several cities,” Tähtinen says.

Tähtinen hopes that hybrid construction will continue to develop. At Sweco, top-class experts in concrete, concrete element, wood structure, wood element, steel, machine shop and glass structure design are found under one roof.

“The main thing is that the construction industry keeps developing and we are able to find the best ways to make and combine materials. This enables our customers to receive a safe end result that meets their requirements,” Tähtinen sums up.

Positive experiences establishing wood construction

A mere decade ago, large wood buildings were considerably less common than today. Kokkonen believes that the proportion of wood construction in all construction will continue to grow. As the number of buildings increases, design and construction methods will become established.

“My belief and hope is that wood construction will increase at the same rate as now, becoming a more common way to build instead of an exception. Experiences in the public sector have been positive,” Kokkonen says.

Mitra’s Managing Director Nurmi hopes that the government will continue to support the use of wood in construction in the future.

“The more positive experiences are generated, the more willing others will be to try and develop the concept. Municipalities are competing for attraction factors and residents, and the world is simply going in a direction that will increase wood construction significantly.”