The Finnish town of Seinäjoki hosts the most extensive cluster of buildings designed by Alvar Aalto in the world. Asmo Jaaksi of architects JKMM explains his practice’s approach to designing a new addition to this hallowed Aalto Centre

The Centre displays Aalto’s masterful touch, ranging from the area’s town planning to the smallest door detail and is an invaluable cultural asset which gives the whole town its identity. Five Aalto buildings make up the Centre: the City Hall, State Office Building, Theatre, the Cross of the Plains Church and the Old Library.

Built in 1965, the Library needed a modern extension to meet today’s demands and JKMM’s design, called ‘Clover’, won the competition for the project. The aim was to create dialogue between old and new. The new library respects the protected cultural environment but, at the same time, takes pride in contemporary architecture. One of the objectives of the design was to find an interface with the typical characteristics of Alvar Aalto’s architecture without imitating it.

The new library stands separate from Alto’s original, although connected by an underground link. Division of the building into three sculptural units was an important decision to be able to blend the large building volume with the surrounding townscape. This generates varied, interesting shapes when viewed from different directions. The exposed boarded-formwork concrete interiors are punctuated by carefully placed windows and larger glazing offering controlled views of the Centre. The view from the glazed Pilkington Planar™ wall in the main library hall is dominated by the highlights of the area: the bell tower or the Cross of the Plains Church and the fan-shaped facade of the original Aalto Library. The heart of the building is the wide staircase, intended for different events and as an informal meeting place, which leads to the collection departments on the ground floor and through the connecting underground corridor to the Aalto Library.

The external skin of the new library is dominated by copper. The darkening pre-oxidised copper sets the new library apart from the whiteness of the surrounding buildings. Copper is not a new material to the area but in the Aalto Centre it is mainly the roofs that feature the material’s beautifully patinated green surfaces. In the new library, copper has been used comprehensively across facades, plinth and roofs – creating a single-material skin.

A special shape of copper shingle was specifically designed for the facades to give the building a highly individual, lively and vivid surface. In some situations, the shingle surface is formed into ventilation slots to accommodate air handling. Copper is also used to form vertical grilles and as a door facing to maintain the material continuity.

Specification

Pilkington Planar™ Triple glazing - agon gas filled with 16 mm cavity

Outer Pane:10 mm Pilkington Optiwhite™ THS (toughened and heat soak tested)

Midlle Pane:6 mm Pilkington Optiwhite™ THS (toughened and heat soak tested)

Inner Pane: 6 mm Pilkington Optitherm™ S3 THS (toughened and heat soak tested)

Glass Fins/Mullions
19 mm Pilkington Optiwhite™ THS (toughened and heat soak tested)

Fittings
Pilkington Planar™ 905J