Sustainability building materials and circularity score of residential buildings

Abstract

Building materials used, approaches and technologies related to the operation of residential buildings influence the environment and climate change. For this purpose, an assessment of environmental impacts and circularity of 11 residential buildings (marked as A) was carried out using the life cycle assessment (LCA) methodology. LCA analysis consisted of four parts. First, the goal and scope were defined. Then, inventory analysis (LCI) entered the assessment using input data. They were needed to quantify inputs and outputs, resource and energy flows, emissions, and other leakages. Life cycle impact assessment (LCIA) quantified the pollutants into impact categories. The last part was the interpretation of the results. Investigated buildings were assessed within a moderate climate zone and "Cradle to Cradle" system boundaries over a lifetime of 60 years. The product and energy consumption phases generally contributed to the highest GHG emissions. In terms of materials, aerated concrete (up to 89.4%), concrete (20-51%) and clay brick (38-47%) caused the highest values for the GWP indicator. The end-of-life phase, including incineration, landfilling and reuse of materials, was quantified in the 0.1-74% range. Quantified global indicators are Global warming potential (GWP), Depletion potential of the stratospheric ozone layer (ODP), and Abiotic depletion potential for non-fossil resources (ADP-E). In this study, regional indicators are Acidification potential (AP), Eutrophication potential (EP) and Formation potential of tropospheric ozone (POCP). A building that achieves higher circularity is the building that makes the most use of renewable or reused resources, so it uses less raw materials. The circularity score representing materials recovery was 23% to 48%. The best circularity score of building E (48%) was due to downcycling (45.8%) and use as energy (32.1%) of applied materials. The lowest circularity score was found for building I, with a value of 23%. The most suitable building in terms of environmental impact and circularity was identified using multicriteria analysis.