{"id":54469,"date":"2024-02-22T10:17:40","date_gmt":"2024-02-22T08:17:40","guid":{"rendered":"https:\/\/www.sweco.fi\/?post_type=showroom_cpt&p=54469"},"modified":"2024-02-22T10:17:41","modified_gmt":"2024-02-22T08:17:41","slug":"bulevardi-31-from-school-to-condominiums","status":"publish","type":"showroom_cpt","link":"https:\/\/www.sweco.fi\/en\/projects\/bulevardi-31-from-school-to-condominiums\/","title":{"rendered":"Bulevardi 31 – from school to condominiums"},"content":{"rendered":"
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The protected educational complex was transformed into classic high-value apartments<\/h1>\n

The change of use continued the life of protected valuable buildings at Bulevardi 31 in the inner city of Helsinki. Sweco’s structural engineers helped transform the old teaching and laboratory premises into Lumo rental apartments with unique details.<\/p>\n

Real estate investor Kojamo renovated 77 classically stylish Lumo rental apartments in Bulevardi 31. The building was based on two protected valuable properties: the laboratory building designed by architect Onni Tarjanne from 1877 and Johan Sigfrid Sir\u00e9n’s New Chemistry, built in 1940 to replace a building destroyed in the war. The chemistry buildings have housed the Helsinki University of Technology and, most recently, Metropolia University of Applied Sciences.<\/p>\n

Both buildings have been extended over the decades with wings and additional floors and are connected by a semicircular staircase.\u00a0 According to Toni Kankare, <\/strong>Director of \u00a0Kojamo’s construction management unit, the building history, conservation values and location of Bulevardi 31 require structural designers to have experience of similar sites.<\/p>\n

“By choosing a partner, we ensured that there is enough expertise and resources in structural design. Sweco’s structural engineers had the right angle of approach to the site, and they familiarised themselves with the history of the building sufficiently before the design.”<\/p>\n

Protected details create unique apartments<\/h2>\n

The chemistry buildings are located in the courtyard of the block, opposite the main building on Abrahaminkatu. The red brick Old Chemistry lags behind the New Chemistry. In the newer part, concise rows of windows attract attention. “The partitions could not even be moved 30 centimetres, or we ended up on the window side,” says Henrik Svartstr\u00f6m<\/strong>, Sweco’s Head of Department for Renovation and an experienced structural designer of valuable buildings.<\/p>\n

The amount of detail was so great that structural solutions could not be duplicated from one floor or apartment to another. The only thing that connected the two buildings was the ground-supported subfloor. Unique details can be seen especially in one of New Chemistry’s apartments. The protected wooden coffered ceiling was not allowed to have penetrations or partition walls.<\/p>\n

“That’s why we used mast partitions, which were attached to the ceiling with cantilevered joints and stiffened with 90-degree angles,” says Svartstr\u00f6m. The empty space between the partitions and the ceiling was filled with painted furniture board and clear glass that lets light from room to room.<\/p>\n

The double slab midsole of the new chemistry was emptied of the old mold ware, and a similar cleaning was done on the brick kappa vaults of Old Chemistry. According to Svartstr\u00f6m, the vaults were mainly left visible. “Suspended ceilings were only built in spaces where building services were used.”<\/p>\n

The load-bearing frame of the new chemistry is otherwise made of brick, but the frame of the new attic apartments was made of steel due to the high fire rating. In ancient chemistry, wood was used where possible. “The frame is made of laminated timber beams, and in the stairwell, the suspended ceiling is covered with three layers of drywall for fire safety reasons,” Svartstr\u00f6m says.<\/p>\n

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Studio-sized attic terraces and steel balconies<\/h2>\n

The room height of more than four metres in the old chemistry building made it possible to build lofts in some apartments, and some of the apartments have elegant steel balconies on the courtyard side. “They were supported with pull bars, which made it easier to transfer the power components to the frame of the house,” says Svartstr\u00f6m.<\/p>\n

In the attic of the new chemistry building you can find the most luxurious apartments. The apartments have five rooms and roof terraces of about 30 square meters. Vacuum insulation was used in the thermal insulation of one terrace, because other types of insulation would not have fit in a space where the height of the roof could not be changed. The biggest challenge in the second corner apartment was stiffening.<\/p>\n

“The exterior walls on the terrace side were almost made of glass, but the shape of the roof was not allowed to change despite the support,” Svartstr\u00f6m says. The pulling forces on the outer walls were controlled by means of a pull bar, which was attached to the ridge rafters and directed in the form of a triangle between the pillars.<\/p>\n

Otherwise, according to Svartstr\u00f6m, only a small amount of reinforcement was needed. “The broken roof of the old chemistry wing was supported with steel beams, but otherwise the structural load-bearing capacity of the laboratory and teaching facilities was sufficient as such for housing construction.”<\/p>\n

The first lucky residents were able to move into the historic building in late 2023. In addition to the location, good feedback has come from the uniqueness of the apartments. For example, the floor height is different from the mainstream.<\/p>\n

“The end result is really great, and the tenants’ comments tell us that we have succeeded,” Kankare says.<\/p>\n

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Photo: Kojamo Oyj<\/p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<\/section>\n\n\n

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