Materials in Germany's domestic building stock: Calculation model and uncertainties

Building stocks are the dominant consumers of resources within national economies. Correspondingly, there is high demand for improved knowledge of material stocks and flows in the built environment. Material flow analysis is well suited to meet this demand. Although numerous studies have been conducted on this topic over recent years, these frequently lack applicability and transferability due to insufficient documentation or treatment of uncertainties. A new approach is presented here to calculate material stocks and flows for domestic buildings using the example of multi-family housing (MFH) in Germany. The approach is critically examined to determine its validity. The calculation process involves four steps: (1) building types are classified according to building age; (2) highly specific material composition indicators (MCIs) are calculated for the respective building types; (3) the total material stock as well as inflows and outflows are derived from the total floor space of Germany's MFH; and (4) validity tests are performed to quantify uncertainties. The main results are age-based MCIs for MFH, the total material mass as well as quantitative information on parameter- and model-related uncertainties. Conclusions are drawn on the validity of results, the scalability and applicability of the model and its implementation, along with potential model refinements.;Building stocks are the dominant consumers of resources within national economies. Correspondingly, there is high demand for improved knowledge of material stocks and flows in the built environment. Material flow analysis is well suited to meet this demand. Although numerous studies have been conducted on this topic over recent years, these frequently lack applicability and transferability due to insufficient documentation or treatment of uncertainties. A new approach is presented here to calculate material stocks and flows for domestic buildings using the example of multi-family housing (MFH) in Germany. The approach is critically examined to determine its validity. The calculation process involves four steps: (1) building types are classified according to building age; (2) highly specific material composition indicators (MCIs) are calculated for the respective building types; (3) the total material stock as well as inflows and outflows are derived from the total floor space of Germany's MFH; and (4) validity tests are performed to quantify uncertainties. The main results are age-based MCIs for MFH, the total material mass as well as quantitative information on parameter- and model-related uncertainties. Conclusions are drawn on the validity of results, the scalability and applicability of the model and its implementation, along with potential model refinements.;