A key presence in contemporary Finnish architecture, Anttinen Oiva Architects completed construction of Finland’s biggest university library, Helsinki University Main Library, also known as Kaisa House. In the heart of Helsinki on Kaisaniemenkatu, the road forming a long curve arching across the city’s checkerboard of streets, Anttinen Oiva’s Kaisa House fits into a city block made up of bare brick buildings, picking up on the same vocabulary in a contemporary style. The project required demolition of an old supermarket, a concrete building which demonstrated little respect for the historic cityscape around it, while maintaining and reinforcing its existing underground levels.
At the entrance to Kaisaniemen metro station, at the point where the tram tracks curve to the west, is the new façade of Helsinki University Main Library, the design of which forms a connection and at the same time a separation on the historic urban façade with its regular geometry. The L-shaped lot is on a slope, with its westward side at the point where Vuorikatu meets Kaisaniemenkatu, in a pedestrian area, and its eastward side facing Fabianinkatu, a secondary street, opening up a direct link between the two roads.
Both sides of Kaisa House have a dense, regular mesh of windows which no longer mark the levels of the floors, but represent the building as a single volume. This is supported by the break in the grid formed by irregular arched windows, one very large one on the eastern side and three on the western side, which “hollow out” portions of the building to literally open up the view of its interior from the city and the street. The main entrance is on the eastern side, two levels above the access to the shops on the opposite side. Inside is a long corridor running the full length of the block.
Visitors are offered a view of formidable depth and height: three elliptical hollows open up in the floors, rising up to the roof and multiplying the light coming in from above, while the interiors offer a new perspective from below and from above, linking all the floors and creating a single brightly lit, pulsating space.
Project: Anttinen Oiva Architects
Location: Kaisaniemenkatu 5, Helsinki Finland
Client: University of Helsinki
Project completion: 09 / 2012
Ground floor area: 31 700 m2
Volume: 131 500 m3
Contractors: SRV (main contractor)
Anttinen Oiva arkkitehdit Oy / design team leader Vesa Oiva
Project management / cost and site management: Indepro Oy
Building services consultant: Pöyry Building Services Oy
Construction-engineering consultant: Finnmap Consulting Oy
Electrical engineering consultant: Pöyry Building Services Oy
Acoustical engineering consultant: Helimäki Acoustics
Doors, windows and shutters in steel
Structure in reinforced concrete
Photographs by Mika Huisman, Tuomas Uusheimo