ERNE promotes sustainable construction in Zurich

05. February 2025

Since June 2024, a new two-unit apartment block has been under construction on Limmattalstrasse in Zurich. The ERNE building construction team in Zurich has so far poured floor slabs, various walls – some of which are exposed concrete – and ceilings, carried out bricklaying work, and constructed beams and ramps.

What makes this project special is that the client requested the use of CO2-neutral concrete. This is not an everyday occurrence for ERNE.

KLARK – climate-friendly concrete – is produced by using a special pyrolysis process to capture the CO₂ naturally stored in wood and mix it into the concrete in a precisely calculated ratio.

By using KLARK concrete, this forward-looking project will enable 300,000 kg of CO₂ to be permanently stored. This is equivalent to the emissions produced by an average new car (Statista, 113 g CO₂ per km) over a distance of 2,645,867 km. That is more than 66 times around the Earth.

Explains Andreas Schefer, Head of Sales at Logbau.

By incorporating this substantial quantity of CO₂-neutral KLARK concrete, ERNE is taking a pioneering role in this regard.

The processing is more challenging compared to standard concrete. Ivan Burkart, the site manager in charge, comments: “The consistency is stiffer than with conventional concrete, the formwork removal times must be strictly adhered to, and the setting process takes longer. Consequently, site procedures had to be adapted to suit the new material.” There are also colour variations due to the carbon deposits. These are particularly visible immediately after demoulding. Over time, the concrete lightens and develops an exceptional texture.

The construction work is expected to be completed by the end of May 2025.

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