Molins contributes to the reduction of 710 tCO₂e at the Tower One building thanks to the use of low-emission Susterra concrete

Molins has contributed to the reduction of 710 tonnes of CO₂ equivalent (tCO₂e) at the Tower One – Porta Diagonal building, located in Esplugues de Llobregat (Barcelona), through the use of low-emission Susterra concrete, as part of a strategy based on structural optimisation and the selection of materials with a lower carbon footprint.

Following the completion of the concrete supply in 2024, the project now has the results of the sustainability study carried out by bis, the engineering firm responsible for the building’s structural design. The analysis assesses the environmental impact of the decisions adopted from the design phase onwards, as well as the materials used, and quantifies the emissions reduction associated with the overall project.

According to this study, the combination of an efficient structural design and the use of low-emission materials has made it possible to achieve a total reduction of 710 tCO₂e, consolidating the project as an example of how collaboration between stakeholders helps drive progress towards more sustainable construction.

The role of low-emission Susterra concrete

The report highlights the contribution of low-emission Susterra concrete to the project. Its Environmental Product Declarations (EPDs) can be consulted here. Specifically, 67.3% of the building’s structural concrete volume was executed using Susterra CEM II/B-M (P-L) 42.5 R cement.

This cement incorporates natural pozzolan as a supplementary material, making it possible to reduce clinker content and, consequently, the CO₂ emissions associated with its production. In addition, its manufacturing process includes a high level of substitution of fossil fuels with alternative fuels.

According to the study data, Susterra cement achieves a 29% reduction in emissions compared to type II cements and a 41.5% reduction compared to type I cements. In the case of the Tower One building, the use of concrete produced with this cement has resulted in a reduction of more than 332 tonnes of CO₂ compared to the sectoral EPD for concrete.

A data-driven and technical analysis-based approach

The study confirms that structural optimisation, together with the selection of materials with a lower carbon footprint and criteria based on proximity and logistical efficiency, makes it possible to significantly reduce the environmental impact of buildings while maintaining technical performance and structural durability.

The full sustainability study, prepared by bis, is available here.