Saving Materials Through Reduced Partial Safety Factors: A Case Study on a Multi-storey Commercial-Office Building

Minimising material use during the design phase is a possible strategy to reduce greenhouse gas emissions from the building environment. The use of design optimisation techniques such as reduced partial safety factors (PSF) decreases the materials required and lowers the embodied carbon and energy without compromising the overall structural safety and functionality of a building. Modern design codes, such as Annex A in DIN EN 1992-1-1, already include opportunities to save materials by means of reduced PSF for reinforcing steel and concrete. Yet, on the side of permanent actions there is also potential to reduce PSF from the recommended value in DIN EN 1990 ( \({\gamma }_{G}=1.35\) ) since permanent actions tend to be considerable, and the respective scatter reduced. On this basis, this study explores the possibility to save materials through reduced PSF for permanent actions \({\gamma }_{G}\) . To this, a case study on a multi-storey mix commercial-office building with load-bearing components made of reinforced concrete is conducted with the aim to identify which components offer the largest potential for PSF to be reduced. The results indicate that foundations and highly loaded vertical slender components can contribute to save materials through reduced PSF. These components carry a large part of the building load and, therefore, offer more opportunities to save materials. The results suggest that optimised design provisions to reduce PSF have the potential to save materials and, consequently, greenhouse gas emissions. This can be an important measure to adopt in practice and, therefore, contribute to the sustainability of the sector.