Building stocks and infrastructures are representing the largest material stock of industrial economies. In order to minimize the use of primary resources, greenhouse gas emissions as well as energy consumption for production of new materials, the “Urban Mining” strategy aims to recycle these urban stocks. Circular City Vienna, as one of the examples of urban policy-making in striving for resources efficient urban built environment, defines the strategy till 2030 in order to guarantee maximal resources efficiency standard for new construction and refurbishment considering thereby location as well as functionality. Thereby the materials and building elements of the demolition-objects have to be re-used or recycled by 80%. For enabling of reduction of material footprint as well as to increase recycling rates detailed knowledge about the composition of building stocks is needed, as well as new methods and digital tools for assessment, modelling and prediction of upcoming material flows in the future. This questions and possible solutions will be discussed and demonstrated on results funded research projects BIMaterial: “Process-Design for a BIM-based Material Passport” – where digital BIM based Material Passports were developed; and BIM_Stocks: Digital Urban Mining Platform: Assessing the material composition of building stocks through coupling of BIM to GIS” – where using Material Passports and innovative Ground-penetrating Radar scanning technology, material composition of existing stocks was assessed, thus building a fundament for a digital material cadaster of the city of Vienna.