Hanasaari B is a coal-fired cogeneration power plant in Kalasatama, Helsinki. The
plant started operation in 1974 and, after 50 years of operation, is being
decommissioned in 2023. Decommissioning the plant is a vital step in the City of
Helsinki’s ambitious goal of becoming carbon neutral by 2035. Due to its large size
and architectural quality, Hanasaari B has become a landmark in the Helsinki skyline
and the heart of residential developments in the Kalasatama area. The present vision
involves preserving architect Timo Penttilä’s original buildings – including subsequent
additions and alterations – as well as new compositions. Timo Penttilä successfully
lightened the appearance of the massive power plant by placing the heaviest
functions at the centre of the plant. He grouped secondary facilities such as offices,
coal conveyors and service buildings in smaller units around the generator building.
As a result, the cubic structures focusing on vertical façade surfaces rise like a great
urban sculpture in Helsinki’s industrial cityscape.
Energy production and consumption, as well as sustainability, form the
common threads for future use of the power station and connect it to the
1. Saving and preserving old power plant as a city quarter composition
Opening the full length of the ground floor to the street
edge. This will make the quarter and buildings approachable
and to create diverse ways to accesses to the core space.
2. Saving and preserving old t. Penttilä Power plant as a city quarter composition
Placing new volumes on top of and in the voids between the power plant
structures. This will strengthen the landmark and its silhouette.
3. Partly perserving the power plant
Preserving the structural skeletons of the larger buildings and
replacing their closed façade surfaces with modern materials.
This will ensure a flexible and contemporary functions.