Amidst the urban developments, Siemensstadt Square stands as a symbol of innovation and progress. The project not only sets architectural benchmarks but also establishes new standards in sustainability. As the developer, Siemens Real Estate (SRE) has set ambitious goals for embodied carbon in the first new buildings at Siemensstadt Square, with the aim of implementing climate protection measures right from the construction phase. Siemens and its IPA partners are working intensively to plan for CO2 savings and use optimized products. A shared commitment, a collaborative process, and innovative partners are key to this effort.

A milestone in terms of the building materials used is the first-ever application of certified Level 4 concrete in the Berlin area. The Environmental Product Declaration (EPD) from EPD Norway confirms an impressively low total GWP of 97.1 kg/m³. This has also been externally verified as a 60% reduction in CO₂ content compared to industry benchmarks—a significant step toward climate-friendly concrete construction.

Focus on Building Materials – SUSTAINABILITY THAT WORKS.

For the concrete pouring of the floor slabs, HOCHTIEF Infrastructure Building Berlin commissioned SCHWENK Beton Berlin-Brandenburg to supply the concrete and the SCHWENK Technology Center to develop the concrete mix.

Typically, CEM III/A 32.5 N-LH (na) concrete from SCHWENK’s Bernburg plant is used for floor slabs, which already meets CSC-CO₂ Level 3 standards. However, this innovative construction project required an even more sustainable concrete: a certified Level 4 concrete.

Development of a new concrete for maximum CO₂ reduction

To achieve this ambitious goal, the SCHWENK Technology Center developed a completely new mix design based on CEM III/B 42.5 L-LH/SR (na) with a total GWP of 218 kg/t, supplied by the Bernburg plant.

Thanks to the excellent performance of this cement, the concrete mix design was further optimized through extensive preliminary testing in Bernburg. The low clinker content—just 19% per ton of cement—posed a particular challenge, as all admixtures derive their reactivity from the cement clinker.

By combining CEM III/B with an optimized mix, CSC-CO₂ Level 4 was ultimately achieved—without compromising on durability and longevity.