What is the SCA?

The Sector-Wide Circularity Assessment is a combination of (1) an urban material flow and stock accounting method and (2) indicators that evaluate the circularity of a sector. It seeks to create an understanding of an urban sector, its economic significance, material flows and stocks, related infrastructure, and stakeholders to capture, assess and present its situation around closed material loops and harmful resource use.

For its application, three steps have to be carried out (see “What are the steps of the SCA?”). In order to better understand the overall picture, the various SCA aspects are described as follows:


To describe the urban and sector context, the SCA requires some main status quo characteristics. For this, data on population, land use and city boundaries need to be collected. By employing those local values, the analysis becomes context specific and relevant to the local sector.

System scope

The “system” that the SCA considers is the sector in a city. The SCA is not only going to be applied to a single project, such as in the case of the CityLoops project the demonstration actions (DA), but the entire sector (see “Sectors'') that they are connected to. The sectors are geographically limited to the city boundaries, although their in- and outflows from outside of those boundaries are accounted for (i.e. imports and exports). This is to stress that it is not a “global sector” that is studied (for instance, the global construction sector).


The SCA was developed for two sectors: construction and biomass. The sectors are defined by the materials that represent them (see “Material scope”). To be informed on the local size and (economic) significance of a sector, the numbers of companies and employees as well as GDP, gross value added (GVA) and names of the associated stakeholders are collected.

Material scope

The material scope of the SCA focuses on the materials that typically make up the main share of a sector by nature, while ensuring that they encompass the materials that were dealt with in the demonstration actions in the CityLoops project. The additional materials that were selected beyond those of the DAs, were calculated to make up a vast majority (> 65%) of the sector’s mass (more detailed information on the calculation can be found in Chapter 3.2.2 of the SCA Method).


Since the goal of the method was to be aligned with and satisfy the definition of CityLoops’ circular economy and circular city definition, the indicators used to evaluate the circularity aim were selected to build on those. The sectors are linked to strategic objectives that attempt to represent if overall the material loops were closed and overall consumption of resources is reduced. A set of indicators was selected for each sector, which can be found as a list here.