When Lasita Aken set out to build their dream home for the Housing Fair, the aim was not only to create a modern, comfortable, and beautiful residence, but also to achieve the smallest possible environmental impact. This time, however, they did something that is rarely attempted in a construction project — they calculated the carbon footprint of the house using two entirely different approaches.

“And the results… were surprising even to us,” said Anu Kull, head of Taasterahastu.

“Our analysis was based on the only available carbon footprint calculation methodology, but we used two different datasets. In one scenario, we used Estonia’s national construction materials database, which is based on averaged environmental declarations from local producers and on values used in Finland,” Kull explained. “In the second scenario, we took a project-specific approach and used the actual environmental declaration data for the materials used in construction.”

The results were alarming. When using the national database, the result showed that the house inevitably generates a carbon footprint. “No matter how carefully we selected materials or how we built — the recommended tool SARV assigned a carbon footprint to the building in every case,” said Kull.

Using the project-specific dataset, however, the opposite picture emerged: the house sequesters more carbon than it releases. In other words — the building has no carbon footprint at all. Since the calculation methodology was identical in both cases, it became clear that the problem lies not in the method but in the emission factors used.

What causes this difference? Kull explains that Estonia’s nationally recommended database is generalised and relies on average values that are, by their nature, conservative. It also contains coefficients that may not reflect the actual environmental impacts of a specific project. A project-specific approach, on the other hand, allows for the origin of the materials used, along with the transport and energy associated with that specific building, to be taken into account. This produces a far more accurate — and often more favourable — result, particularly when bio-based and low-carbon-footprint materials have been used.

What does this mean for construction in Estonia? The Lasita Aken experience demonstrates that:

  • using high-quality, transparent, project-specific data can make the mapping of a building’s carbon footprint considerably more accurate;
  • a carbon footprint is not inevitable when informed and considered choices are made;
  • the national database requires further development to provide a fairer picture of environmentally sustainable buildings.

If we genuinely wish to move towards carbon-neutral construction, we must give builders and designers tools that recognise real efforts — rather than penalising them through generalisation, as the Lasita Aken experience confirms.

“In conclusion, our small experiment confirmed a great truth: accurate data and conscious material selection can dramatically alter a building’s environmental impact. Not every building must necessarily leave a footprint — with well-planned and wisely chosen solutions, a building can help to improve the environment rather than merely harm it. And that is precisely the future we want to build,” said Anu Kull.

The Housing Fair takes place in Jõelähtme from 4 to 15 June. For the fair, 12 contemporary homes and inspiring buildings — designed by leading Estonian and international architects with the freedom to experiment, create, and offer something truly exceptional — are being erected as a separate village within the Estonian Golf & Country Club Golf Resort development. The house being built by Lasita Aken is on plot No. 1.

Published on ehitusleht.ee, 30 April 2025. https://ehitusleht.ee/kas-susinikujalg-on-paratamatus-elamumessi-kogemus-naitab-vastupidist/