The coming renovation of the Lahti City Hall will take energy efficiency and carbon neutrality into account. © City of Lahti/Lassi Häkkinen
Chosen as the European Green Capital of the year, Lahti has already committed to carbon neutrality by 2025. Lahti, a pioneer in the circular economy within the Circwaste project, is at the forefront of environmental and climate sustainability in a variety of sectors. Last year, one previously overlooked aspect was identified.
“Land use and civil engineering are a small source of carbon emissions compared to energy solutions, but buildings do contribute to determining how much energy is consumed,” says Juhani Pirinen, Director of the Carbon Neutral Construction Development Center and man behind the idea. “We need new ideas that promote environmentally friendly construction starting with zoning.”
The City of Lahti supports the activities of the new development centre in a very practical manner. “The City’s upcoming zoning and construction projects will serve as pilot projects for different solutions,” Pirinen says. The Confederation of Finnish Construction Industries RT is also involved in the development centre as well as local companies, developers and educational institutions. “The LAB University of Applied Sciences, the LUT University and the University of Helsinki have taken the responsibility in regard to research and development projects.”
Projects develop construction industry practices
The Carbon Neutral Construction Development Center focuses on global megatrends: renewable energy production, minimisation of energy use, recycling of demolition materials and use of organic materials in buildings as carbon sinks. In Lahti, too, there is a desire to develop wood construction.
“There are about 150 companies in the wood industry in Päijät-Häme, providing us all the prerequisites for learning how to build sustainable wooden buildings that contain a lot of carbon. In addition, it must be possible to demolish wooden buildings in a way that allows the materials to be reused, not just burned,” Pirinen emphasises.
One of the development projects financed by the Ministry of the Environment is to create new guidelines for the builders of wooden blocks of flats. “We want to develop the operating methods of the sector in order to ensure that developers’ design decisions do not limit the implementation options of wooden blocks of flats. Suppliers of timber products must be able to offer their own solutions to projects.”
Another example of newly launched development projects is the Green Building Council Finland. “We guide housing companies to develop carbon neutrality in their own operations,” says Pirinen. Funding has also been sought for a research project investigating the converting the heating system of a terraced housed from oil-based to renewable energy. “Carbon neutrality requires site-specific hybrid solutions, so we aim to find out how terraced houses can improve their thermal insulation, recover waste heat, utilise renewable energy and store it in batteries and hydrogen.”
Sustainable demolition projects are part of low-carbon construction
The centre also wants to promote low-carbon construction through sustainable demolition of buildings and the recycling of building materials. “We are starting a research project aimed at developing a functioning ecosystem in Lahti, which will help us restore materials such as concrete, bricks and mineral wool from demolition sites back to the built environment.”
One of the biggest obstacles is that the demolition materials are labelled as waste. “The product approval directives make it difficult to recover demolition materials for use as building materials, even though demolition concrete, for example, is immediately separated into clean and dirty material. That is why the promotion of circular economy in construction requires changes to legislation and practices.”
The Lahti Carbon Neutral Construction Development Center aims to become a national knowledge base and centre of expertise in carbon-neutral construction. “We are developing Finnish technological know-how, equipment and products while also lowering the City's carbon emissions and creating vitality in Päijät-Häme. Right now, there is a need for Finnish expertise all over the world.”
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