Toward zero-emission buildings: A case study on a non-residential building in Germany using life cycle assessment and carbon sequestration of green infrastructure

Regarding greenhouse gas (GHG) emissions and further environmental impacts, such as acidification potential (AP), eutrophication potential (EP), and pollutants, the building sector plays an essential role in the global transformation toward a climate and environmentally friendly industry. In this paper, a non-residential building in Germany is analyzed regarding various emissions (GHG, AP, EP, pollutants, acoustic, light, and radiation) and the primary energy demand (PERT, PENRT) during its life cycle of 70 years. Life cycle assessment (LCA) according to DIN EN ISO 14040/14044 and DIN EN 15978 is used to determine and allocate the environmental impacts of the building. Building emissions are compared to the compensation potential of the green infrastructure onsite. Based on scenario analysis, recommendations to reduce the building emissions are given. The results show that there are emissions in every life cycle stage of the building. Using green instead of conventional electricity for operational energy reduces GHG emissions, AP, and EP by more than 90%. Emissions that already occurred can only be reduced or compensated slightly: the carbon sequestration of the building's green infrastructure and its outdoor facilities can compensate nearly 6% of the total GHG emissions. Therefore, the authors claim that strategies to avoid, reduce and compensate emissions should take place in early planning phases to realize zero-emission buildings.