# Sustainability Assessment on an Urban Scale: Context, Challenges, and Most Relevant Indicators
## 4 Discussion  
BREEAM-C, LEED-ND, SBToolPT_Urban, and SNTool (minimum version) are presented and compared in this research. Based on the issues that they address, the study reorganized the most relevant urban sustainability indicators into 12 categories. Indicators in the analysed methods that have different names but address similar issues and aspectsare considered the same and organized under the same title (Table 2). Moreover, the charts provided for each category (Figures 1-12) show the level of popularity of each indicator among the studied methods. Additionally, this determines whether they are addressed by ISO 37120 standards for sustainable communities and the SDGs of Agenda 2030. The final list of indicators is based on the level of the frequency of distribution for each indicator in the selected methods, ISO and SDGs. Some indicators comprehend more than one sustainability issue, while each of those issues is considered a separate indicator in some methods. The study considered several sustainability issues in one indicator in the final list, creating mixed indicators that gather all the interrelated issues. This approach aims to ease a better understanding by the design teams of the most important sustainability principles to consider in the design of sustainable urban areas. The final list comprises 32 indicators, organized into 12 sustainability categories (Table 3). Figures 13-16 compare the frequency of the indicators between the analysed methods. The comparison shows that:  
1. Eleven indicators are promoted by all of the methods and supported by ISO 37120 and/or SDGs (Figure 14). These indicators were chosen for the final list, with four of them being proposed in a mixed-mode format. 2. Thirteen indicators are promoted by at least three methods and supported by ISO 37120 and/or SDGs (Figure 15). These indicators were chosen for the final list, and three of them were proposed in a mixed-mode format. 3. Five indicators are promoted by two to three methods but are not supported by ISO 37120 and/or SDGs (Figure 16). These indicators were chosen for the final list, and one of them was proposed in a mixed-mode format. 4. Eight indicators were promoted by two tools and supported by ISO 37120 and/or SDGs. Five of these indicators were chosen for the final list, and two of them were proposed in a mixed-mode format. Based on the shown data, the most popular indicator is the availability of public transport services (Figure 14), which is expected because efficient and effective urban transport can significantly contribute to achieving objectives in a wide range of urban sustainability domains, e.g., reducing energy consumption and GHG emissions, which are the core focus of sustainable development. The second most common factors are the availability and proximity of vital local public services and pedestrian path accessibility, which are related to connectivity, ensuring ease of movement and convenience for commuters, which also results in lower fuel consumption and GHG emissions. The next most popular indicator is the enhancement of ecological value and conservation of native species (as shown in Figure 14), which was expected because protection and enhancement of existing ecological features are advocated to minimize biodiversity loss on the planet. Furthermore, the inclusion of the indicators in the ISO and SDG lists is also regarded as an approval of the indicator's significance. The analysis of these assessment tools reveals that, although they were developed to address different contexts, they rely on a similar list of sustainability indicators. This means that there is a common international agreement about the main categories and sustainability indicators to assess sustainability at the urban level. The findings of the analysis highlight that certain sustainability criteria have a higher importance in the reviewed urban sustainability assessment tools, while others are considered less important. For example, as shown in Figure 13, an indicator such as adapting to climate change was frequently overlooked.