In English | ISSUE 1/2025
Kulma21 – Modern office block implemented on old building frame
The Student Union building of the Helsinki School of Economics in downtown Helsinki was reformed in a challenging refurbishment project into a modern office block. The facade of the architecturally esteemed building was restored to its original appearance. The Building had been inaugurated in 1941.
In the refurbishment project, the Building was renovated to a standard that meets modern requirements. The building frame consists of solid brick walls and a column-beam and reinforced concrete frame. Several challenges related to structures had to be overcome.
The interior areas were completely renovated and the intermediate walls as well as the base floor were dismantled. The original seventh floor attic was rebuilt to contain offices and sauna facilities. The structures of the seventh floor underwent an almost complete replacement. The new storey was designed as a hipped mansard roof, which meant that special requirements applied to structural implementation and roof ventilation.
The facade was restored to its original appearance with triple coat plaster and new windows of wooden construction, adapted to the old model. The new facade materials used were chosen based on the original 1940s materials.
Building systems integration and precision design were implemented using Tekla Model Sharing. It proved possible to retain the Building frame and the intermediate floors and the basement areas were given a useful purpose. This would not have been possible without modelling. Continuous cooperation with the Building systems designers was required to resolve issues related to ceiling heights and ventilation routed between the beams.
The refurbishment of Kulma21 fulfilled the Excellent level rating criteria of BREEAM environmental certification. Carbon footprint calculation shows that emissions due to the building are 44% lower than those of a corresponding new-build. The project was awarded an Honorary Mention in Tekla BIM Awards Finland 2024 competition.
More information available at:
https://www.tekla.com/fi/bim-awards/kulma21
