Environmental Structure of the Year 2025 Award goes to Kalasatama-Pasila tramway
According to the jury, tram line 13 from Kalasatama to Pasila in Helsinki had several key strengths. Overall, the tram line was seen as an ambitious project in every respect, and public transport was designed from the outset to be part of the existing urban structure, revitalizing and greening it, according to the award criteria.
"The tram line is a great example of a project that brings different elements together and is also clearly visible in the everyday lives of city residents", said chair of the jury Kaisa Koskelin from the Finnish Association of Landscape Architects.
The project included the construction of a tram line from Nihti via Kalasatama to Pasila, as well as numerous streets and green areas connected to the project. The 4.5-kilometer cross-town connection was integrated into the existing public transport network, ensuring smooth connections for commuters and residents in the area. In addition, the tramway to be built will connect to the Kruunusillat tramway in Nihti, which is expected to be completed in 2027.
According to forecasts, Kalasatama district will have a population of approximately 25,000 and 10,000 people will work in the area by 2040.
Diverse urban nature as a guiding principle
Sustainable construction solutions, preserving biodiversity, and creating a pleasant urban environment were the guiding principles of the project.
Strengthening the urban biodiversity was identified as one of the key priorities of the project's responsibility work. This is reflected in the creation of novel ecosystems, multi-species plantings, and the maximization of vegetation even in unusual places, such as rail areas and tram stop roofs.
Key role in the project played experts from Aalto University: Associate Professor Elisa Lähde, who was responsible for sustainability and developed interdisciplinary sustainability solutions for the project, and doctoral researcher Olivia Mahlio, who worked as a landscape architect and was responsible for street environment design, particularly on Hermannin rantatie.
“Sustainability was built into the project as part of everyday planning decisions through interdisciplinary work. The award sends an important message that ambitious responsibility work is valued and that an infrastructure project can also be a landscape and urban development project”, says Elisa Lähde.
Exceptionally diverse street vegetation was also implemented along the tram line on Hermannin rantatie road: 15 different tree species were planted along a distance of only 850 meters, and on sunny and dry habitats, steppe plantings were used, and seed banks from ruderal areas were utilized by recycling topsoil.
"The goal on Hermannin rantatie was to create a functional, pleasant, and green street environment where solutions that support biodiversity are part of the whole—not separate additions," explains Olivia Mahlio.
The alliance model enabled ambitious responsibility work
The project was implemented using an alliance model, in which the client, designers, and contractors formed a joint team. The model created a strong foundation for experiments, workshops, and innovation, and helped to take sustainability measures from plans to implementation.
Sustainability solutions began to be developed as early as the preliminary study phase, and the implementation of responsible measures was confirmed in November 2024 with the BREEAM Infrastructure environmental rating, which the Kalasatama to Pasila project was the first tramway project in Finland to receive. The project achieved a commendable rating.
The street environment along the tramway became more pleasant, attractive, and safer. Conditions for walking and cycling also improved significantly.
The Environmental Structure Award of the Year was announced on Wednesday, 11 February, at the ViherGala in the Pavilion, Jyväskylä.
Further information:
Associate Professor Elisa Lähde, Aalto University, +358 50 471 9141, elisa.lahde@aalto.fi
Doctoral researcher Olivia Mahlio, Aalto University, +358 50 4110998, olivia.mahlio@aalto.fi
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