This research investigated in which ways the material environmental impact of the main load-bearing structure of a high-rise building can be reduced. To determine this material environmental impact, the shadow price for each material and product has been determined by using ten environmental impact categories. One of these categories is global warming potential.

In this research the material environmental impact of the main load-bearing structure for the building for the European Patent Office has been determined and optimized. The originally designed main load-bearing structure for this building consists mainly of steel columns and beams, and Slimline floors.
The optimisation has been done for a design lifespan of 50 years and for 200 years. Additionally, a higher live load that creates more flexibility for the 200-year scenario is examined. The original function for the building is “office” and the other considered function is “meeting”.
As alternatives for the beams and columns, steel, concrete, and timber elements have been considered. Hollow core slabs and Lignatur floors were explored as alternatives for the Slimline floors.

In this research it has been found that it is beneficial to prolong the design lifespan of building. The environmental impact per year is much lower for a lifespan of 200 years than for a lifespan of 50 years. In order to increase the chance of a longer lifespan, it is wise to create flexibility concerning the function of the building. A higher live load will result in slightly more material needed, but still, the environmental impact per year is much lower than for 50 years.
Additionally, there can be looked at choosing the best material for each application. For a design lifespan of 50 years, the difference between the materials is such small, that no preference can be determined. For a lifespan of 200 years the differences are still small, but an entire steel structure or a combination of steel beams and concrete columns result in the smallest environmental impact. For floors, no matter the lifespan, with a big span and where no in-situ concrete can be used, hollow core slab floors proved to be the best choice.