by Rick Pruetz, Vice President, Ecocity Builders

The European Commission has named Lahti, Finland, as the 2021 European Green Capital in a competition that included nine cities from seven countries. The jury praised Lahti for its strong performance across a wide range of environmental categories including biodiversity, air quality, waste management, and eco-innovation. Ecocity Builders is honored that Lahti plans to celebrate its year-long reign by hosting an Ecocity Forum on November 1-2, 2021.

Lahti was originally known for agriculture, forestry, and carpentry. But after World War Two, industrialization caused the city to grow from roughly 30,000 to its current population of 120,000 inhabitants. Rapid industrialization and urbanization also caused eutrophication of adjacent Lake Vesijarvi. However, Lahti has since cleaned the lake and continues to demonstrate its sustainability chops in greenhouse gas mitigation, renewable energy, climate adaptation, transportation, land use, green space, and ecosystem restoration.

Between 1990 and 2017, Lahti reduced total carbon dioxide emissions by 41 percent and per capita emissions by almost half. Over 80 percent of the buildings here are served by district heating, which is the heating source for more than 90 percent of the population. Over 95 percent of Lahti’s district heating is generated by highly-efficient combined heat and power plants. Lahti is completely eliminating coal-fired generation and its new power plant is fueled by certified sustainable wood and biomass sourced from within a 100-kilometer radius. Based on its past success at reducing energy consumption, Lahti will likely reach its goal of being carbon neutral by 2030 and carbon negative by 2050.

Lahti showcases renewable energy in its municipal services, such as the kitchen that prepares 10,000 meals daily for schools, which is powered by district heating, heat pumps, energy recovery, and solar panels. For the World Nordic Ski Games in 2017, Lahti installed a 460-panel solar system in its winter sports arena. Lahti uses its Green Ratio calculator and KEKO tool to guide climate change mitigation and adaptation considerations within a continuous master planning process.

In addition to mitigation, Lahti is actively preparing climate change adaptations for projected increases in precipitation and average temperature as well as heavy rains, heatwaves, and wind storms. Among Lahti’s various strategies are green roofs, maintenance of 10,000 street trees, and new management approaches for the 7,000 hectares of forest owned by the city. Lahti also plans to increase its ability to sequester carbon by increasing carbon sinks with nature conservation projects.

Progress is also being made on lowering emissions from the transportation sector with the assistance of a personal carbon trading program that was launched in 2020 using a smart-phone application that calculates carbon emissions by mileage and mode of transportation. Lahti’s compact development pattern puts 75 percent of the population within five kilometers of the city center and nearly all public transport routes meet at the city’s Travel Centre. Lahti aims to double the percent of trips taken on public transport and bicycles by 2030. By the end of the decade, the city wants 45 percent of all trips to occur by walking or cycling.

Lahti is rapidly making its car-dominated roadways into a more human-friendly, multi-modal network. Market square in the heart of the city was transformed into a public space by moving cars from a surface parking lot to an underground structure. A state of the art bike path on Vapaudenkatu street was extended to implement a part of the 2025 Walking and Cycling Plan which would put most parts of the city within a 45-minute or less bike ride of downtown. The city has added other car-free zones, such as Lanu Square, and made downtown streets more pedestrian-friendly by replacing parking lanes with bike paths and wider sidewalks on selected streets.

Roughly two-thirds of Lahti’s population growth occurs within the existing developed areas of the city, an impressive accomplishment made possible largely by the redevelopment of brownfields. The former harbor area has been transformed into a high density, mixed-use neighborhood of primarily multi-story residential buildings accessed by pedestrian/bicycle-friendly streets and a path along Lake Vesijarvi. The crown jewel here is Sibelius Concert Hall, a repurposed industrial building that now serves as the home of the Lahti Symphony Orchestra.

In addition to compactness, Lahti’s development pattern puts almost all inhabitants close to greenspace. The most prominent feature of the city’s green structure is Salpausselka, a forested, glacial ridge that forms a green east-west corridor extending into the city center. Lahti’s green structure map shows many of the city’s lakes and forests, which constitute over 80 percent of the city, linked to the green spine of Salpausselka, The city protects existing wetlands, wildlife habitat, and groundwater recharge zones while establishing new green features like the network of streams and wetlands constructed at Karisto, three miles east of downtown.

National legislation protects the biodiversity of 995 hectares of Lahti including the Natura 2000 sites of Pasakallio and Linnaistensuo. In addition, the city has designated 1,933 hectares in over 400 smaller sites as representative of various habitats including old-growth forests, cliffs, springs, small rivers, ponds, and individual trees. The city owns 7,000 hectares of forests, of which 40 percent are over 80 years old. Together, these habitats are home to numerous species including the Siberian flying squirrel and the European otter.

To revitalize its blue zones, Lahti has steadily eliminated pollution sources, built 20 wetlands, and added more water management features in its already successful transformation of the previously contaminated Lake Vesijarvi. As an indication of progress, there are now several swimming beaches along its shore and the aquatic habitat has improved to the point where the lake is now used to restore populations of a critically endangered species of eel.

In addition to showcasing these accomplishments, Lahti’s Ecocity Forum 2021 will demonstrate the world’s first personal carbon trading program as well as other apps, information systems, and digital tools needed to accelerate the vitally-important transition to 1.5-degree cities and citizens. To learn more, visit Lahti’s Ecocity Forum 2021 website at HOME | Ecocity Forum 2021 | Eventos.


Lahti. 2019. Application – European Green Capital 2021. Accessed at

About the author

Rick Pruetz

Rick Pruetz, FAICP, is Vice President of the Ecocity Builders Board and an urban planner who writes about sustainability, most recently Ecocity Snapshots: Learning from Europe’s Greenest Places and Smart Climate Action through Transfer of Development Rights.