Old Rauma got a multi-use campus suitable for the wooden house milieu

A wood-clad hybrid building is about to be completed next to Rauma’s Old Town, serving several user groups from schoolchildren to hobby clubs. The structural design, energy-efficient HVAC technology and smooth traffic arrangements of the Kari campus were the responsibility of Sweco’s experts.

The Kari campus, which will be completed in early spring 2024, is a versatile sports, leisure and school centre next to the UNESCO-listed Old Town of Rauma. The extensive project was based on indoor air problems at Nortamo Comprehensive School.

“The city decided to expand the swimming hall project so that facilities could also be located in the same building for a school, music and adult education centre,” says Kimmo Salminen, Construction Manager of the City of Rauma. When youth facilities were added to the complex, the campus was supplemented with a sports hall of approximately 1500 square metres with a seating capacity of 800 people.

Salminen considers the campus building to be a significant project for both the city and its residents due to its versatility and central location. “The city centre is only 300 metres away, and next door there is a library and a sports area with ice and training halls.”

Energy recycling reduces the need for purchased energy

When the design of the project was put out to tender in 2018, Sweco was chosen as the designer of structural and building services as well as traffic areas for clear reasons. “Price and quality met,” Salminen sums up. Solid experience was needed, for example, in the structural and HVAC design of swimming halls.

The City of Rauma defined precise energy efficiency targets with the help of a separate energy consultant and multi-objective optimization. The consumption of purchased energy was reduced, for example, by thoroughly recovering heat from the swimming hall’s wastewater and ventilation.

“Heat is recovered first with the compressor-condenser unit of the ventilation unit and then with heat pumps,” says Jyrki Vuorio, Sweco’s HVAC Design Director. In addition to heat pumps, district heat is used on campus, the return water of which keeps yard areas thawed in winter. “Energy recycling significantly reduces the need for purchased energy.”

The building has many user groups, which is why demand-controlled ventilation was designed as several independent entities. “There are a total of 36 IV machines,” Vuorio calculates. Most of them are combined with cooling, which, among other things, takes care of comfortable conditions in school classrooms. In addition, space-specific coolers are used.

Controlling indoor conditions is especially important because the swimming hall produces moisture, especially in the glass-surfaced and tall central lobby. “Air circulation and blowing have been designed so that there is sufficient air movement also in the upper parts of the lobby,” Vuorio says. Among the special solutions, he highlights the sprinkler system. “It uses pool water from the swimming pool instead of an external water source.”

All building technology is controlled by comprehensive building automation, for which the City of Rauma issued clear design instructions. Carbon dioxide amounts and temperatures are monitored on a farm-by-farm basis, but adjusted according to zoning. “The multi-objective optimization showed that zone-specific adjustment is sufficient: the different spaces are used comprehensively and evenly from morning to evening,” Salminen says.

Hybrid of wood, steel and concrete

The Kari campus is architecturally connected to the wooden house milieu of old Rauma. Solid wood glulam slats have been used for the façade. “Their fastenings were designed separately so that they could be placed on the façade in the desired way,” says Janne Väinölä, Sweco’s structural engineering project manager and BIM manager. Glulam has also been used as a frame for the glass walls of the central lobby and swimming hall.

Otherwise, the frame of the building consists of prefabricated walls and columns, as well as intermediate and upper floors cast in situ or hollow-core slabs. The roof of the sports and swimming hall also has sturdy steel trusses with long spans. “The welded WQ trusses required special design, and hollow-core slabs were added on top of them,” Väinölä says.

The heart area of the campus is the central lobby, which offers views of all facilities. The architecture of the lobby roof is supported by an impressive steel star truss, the success of which was verified by a third-party inspection. “The cooperation between Sweco and partners went well, and the discussion was developing and positive,” Salminen praises.

Safe passages for all users

The campus will open to users in autumn 2024, and the traffic arrangements that Sweco’s traffic planners will consider together with landscape architects will also be tested. “We were able to fit parking spaces in accordance with the plan in the yard area and parking facility so that a large part of the area remains for other uses, such as children’s recess areas,” says Mikko Suhonen, Department Manager at Sweco.

The connection arrangements from the streets to the yard area work from the perspective of motorists as well as pedestrians and cyclists. The parking area is guided from one exit, and service traffic uses its own exits. There are private parking spaces for cars, buses, bicycles and mopeds. “This way, traffic is smooth and safe both during school days and in evening use,” Suhonen emphasises

Picture: The City of Rauma and Verstas Architects