The document presents an accounting method for cities to evaluate the circularity of their construction and biomass sector(s). Firstly, it goes through some general definitions and concepts of circularity in cities and sectors. The next section showcases the proposed sector-wide circularity assessment method and discusses related data needs, processing, and analysis. This method combines material flow accounting and key “circularity” indicators to assess circularity in economic sectors. The developed method seeks to find a balance between scientific rigor and comprehensiveness on the one hand, and operability by urban policy makers and practitioners on the other. Finally, this document provides a handbook for urban policy makers and practitioners on how to apply this method for the biomass and construction sector of their city.