Largest wooden school in Finland implemented sustainability with a life cycle model

The new wooden Mansikkala School in Imatra will be built in the middle of the school campus by the Vuoksi River. The project will be carried out by YIT using a life cycle model, and the components for the wooden frame will be supplied by Oiva Wood Solutions. Sweco handled the preliminary design, element design and main structural design of the structures for the largest wooden school building in Finland.

The wooden Mansikkala School is the largest investment in history for the City of Imatra. At the same time, it is an important step in the refurbishment of the school network, which involves a transition from the somewhat dilapidated small schools to three school campuses. Mansikkala is also a demonstration of the core values of the City of Imatra and concrete actions in sustainable urban construction.

“We want to be responsible in terms of the climate and the environment at all levels of construction,” says Lassi Nurmi, Managing Director of the City of Imatra’s development company Mitra. Imatra will implement a large-scale solar power project, and excess industrial slag will be utilised in infrastructure construction alongside natural stone. “Energy-efficient geothermal energy will be used to heat and cool the new wooden school.”

Life cycle model also ensures systematic maintenance

Mansikkala School will be implemented using a life cycle model which involves YIT handling the maintenance for the coming 20 years, in addition to designing and constructing the building. Mansikkala is an exceptional project for YIT.

“The school is the largest individual wooden building that we have implemented with the life cycle model,” says Matti Varstala, YIT’s Design Director for Life Cycle Projects. The life cycle approach steered all aspects of design. In addition to this, the funds that will be required for maintenance have been earmarked in advance. “The budgets of municipal operations are tight, which means that repair debt is easily accumulated. The life cycle model prevents corner-cutting in maintenance since the building must be handed over in the predefined condition after the agreement period.”

The biggest challenge with the life cycle model is taking multiple perspectives into account. According to Varstala, modern school buildings are complex and the technical systems alone require plenty of space and adaptation.

“We aim to optimise everything as best we can and put together a building that is easy to maintain and reliable far into the future,” he explains. “Sweco’s designers have borne the main responsibility in terms of fitting together the varying needs and finding the right compromises. It’s been challenging, but we’ve made everything work.”

Wood element construction speeds up schedules

The school of some 16,500 floor square metres comprises two floors intended for teaching activities and the machine rooms in the attic. In the autumn of 2020, the new school will be admitting some 1,350 children and young people from day care children to upper secondary school students.

“At the moment, we’re focusing on modification engineering and ensuring that the end result is a high-quality building that meets the end users’ needs,” says Hannes Tähtinen, Sweco’s Wood Technology Manager. The school will be constructed using an adaptable module division, which will create clear lines and open spaces in the indoor spaces. “Versatility is important in modern schools. Group sizes vary and the school also serves as a multi-purpose building for city residents and a meeting place for associations.”

Prefabricated wood and concrete elements have been used to construct the Mansikkala School. Concrete has primarily been used as a stiffening structure, and the intermediate floors, pillar beams and facade have been made from wood. The benefits of element construction are the high degree of prefabrication and the precision of even the largest elements. “Constructing elements in controlled factory conditions as far as possible reduces time spent at the worksite significantly. It also ensures that the load-bearing structures are easier to connect to building services and automation,” Tähtinen says.

The City of Imatra is now convinced of the benefits of wood element construction. “It has made a massive difference in terms of schedule,” Nurmi says. “We’ve been able to overlap design and implementation, finishing the module element installations of a building during the implementation planning of another, for example.”

Making wood construction commonplace like information models

The implementation of the diverse project on a tight schedule has required smooth information flow. The information model has been an essential tool for work task division.

“When everyone uses the same information model, the designers have fast access to the necessary information and production gets material specifications in advance, even though element design is still under way,” Tähtinen says. Sweco’s SmartDrawings service was also used in the wooden element construction. “Production at the Oiva Wood Solutions factory could use a tablet to view the information model for the element to be manufactured and supplement the details in the manufacturing drawing.”

YIT’s Varstala has no fondness for past times when information models were not accessible to everyone. “The school project has once again demonstrated the power of information modelling in merging different design areas and rooting out conflicts in advance.”

Varstala also hopes that wood construction will become more commonplace in the same way. “At the moment, public wood construction at this scale requires the client to have a strong desire to use wood specifically. However, wood construction has an immense amount of development potential, and all we need now is more successful experiences in the vein of Mansikkala to create a positive snowball effect. A change will materialise one project at a time!”

Image: Forecon Oy/Tuomas Laitinen