When talking about the construction sector and sustainability, one question comes up more and more often: how can we make better use of the buildings and materials we already have, in a way that is both environmentally and economically sensible? FinEst Centre for Smart Cities is exploring this question in its new project “Reusing old buildings for circular construction”.

The project is led by TalTech researchers Simo Ilomets, Ergo Pikas and Wolfgang Dieter Gerstlberger and Anneli Simm from FinEst Centre for Smart Cities, with Tallinn and Valga in Estonia and Cēsis in Latvia as partner cities. Hundipea OÜ, a company planning a new urban district in North Tallinn, is also involved and hopes to apply the solutions in the near future.

“The best building for our planet is the one that doesn’t exist, because then it has no environmental impact at all. The second-best is the one that already exists and can be reused,” says project lead Simo Ilomets. According to him, this is not only about recycling individual elements or materials, it is about rethinking the entire construction process.

Using the Hundipea area as an example, Ilomets explains that the old industrial buildings there need to be transformed to create high-quality urban space. “Our goal is to find ways to adapt existing buildings or recover elements from them that can serve as donor parts for new transitional buildings,” he says. This means that “old” does not automatically mean “useless”, with the help of science and technology, old buildings can be carefully taken apart so that their components and materials can begin a new life.

A construction revolution: making circularity the norm

The construction industry is heavily regulated and change tends to move slowly. “When people buy a new apartment, they are used to the idea that it is built entirely from new materials. Seeing reused components can raise questions like are they safe and durable?” says Ilomets about the challenges ahead.

Regulations are also not yet fully adapted to allow buildings to be systematically dismantled and their parts used again. One of the project’s goals is to develop the standards and guidelines needed to make this possible.

If the project succeeds, it could help shape a new construction standard where new buildings are created from the parts of old ones. Such an approach could make the construction sector far more resource-efficient and allow cities to grow without causing massive environmental damage.

“This is not just a scientific experiment. We want to create something that actually works and can be widely used,” Ilomets emphasises.

Comment: Mari-Liis Kell, Head of Green Technologies at Hundipea

According to Mari-Liis Kell, Estonia’s official documents state that more than 70% of materials from old buildings are currently being reused, but the quality of this process is low.

“We crush concrete and use it as filler in the ground and everything that burns goes to incineration. At Hundipea, we hope that in the future the main materials from demolition could be given a new life in a higher-quality way,” she says.

The construction sector still relies mainly on virgin raw materials, which brings a very high CO₂ footprint and adds to the global biodiversity crisis.

“If you send the materials from demolished buildings to landfills and at the same time produce new ones for new buildings, it wastes resources and is neither climate- nor environmentally-friendly,” Kell explains.

In her view, materials from old buildings are actually a valuable resource that can be ‘mined’ from the built environment. This would also reduce pressure on nature. Reuse should prioritise direct reuse, then reprocessing into new products, and only as a last resort low-value uses such as filler or incineration.

Kell says it is still difficult to estimate the real market potential for reusing old buildings in Estonia. “To understand this better, we launched a challenge called ‘Reusing Old Buildings’ under the FinEst Centre Smart City Challenge, asking Estonian and Finnish researchers to help us find better ways to reuse materials.”

She adds that digital tools will be key: “Many barriers to circularity are simply about not knowing. We don’t know where materials are, how much of them exist, who needs them and how they could be used. To solve this, we first need the right tools.”

At Hundipea, there is already a clear wish to use materials from existing buildings in the construction of new ones, but there is still a lack of practical methods. “We need clear and simple approaches that can show how to make these materials available without endless extra studies, and that also meet EU regulations. We hope that this project creates useful practical knowledge for private companies and give us a clearer picture of how to reuse materials from the existing Hundipea buildings,” Kell says.

Article source: https://trialoog.taltech.ee/

The implementation of pilot projects is funded by the European Regional Development Fund and the Estonian Ministry of Education and Research through the project “FinEst Targa Linna tippkeskuse piloodiprogramm“.

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