## 3 Methodology
### Development of the Weighting System  
Panel weighing is considered the most accurate method for defining the weighting system of a BSA method [24]. The more prominent and representative the panel, the more precise the result is. In this study, the Analytical Hierarchy Process (AHP) panellist's method was applied to evaluate the relative weight of each indicator. The AHP is an organisational and analytical mathematical method for complex priorities and decisions. It was developed in the 1970s and prioritised human decision making in different fields such as policies, business, project selection, healthcare, and education [25].  
The AHP is a simple technique that can translate the decision-makers' qualitative and quantitative data evaluations into multi-criteria rankings. In addition, the AHP includes a valuable tool for checking the consistency of the decision-makers' evaluations, thus reducing bias in the decision-making process [26].  
The AHP involves the following steps to hierarchise the priorities of a project [25]:  
* Modelling the problem as a hierarchy containing the goal decision, alternatives for reaching it, and criteria for evaluating;
* Establishing priorities among the elements of the hierarchy by making a series of judgments based on pairwise comparisons between them;
* Synthesising these judgments to yield a set of overall priorities for the hierarchy;
* Checking consistency;
* Achieve a final decision based on the results of this process.  
The professionals were asked to provide their opinion on the importance of the five sustainability areas (environmental, sociocultural, functional, economy, technical, and site) in the overall building sustainability level. Inside each sustainability area, the respondents ranked the importance of each indicator using the five-point Likert scale presented before. Based on the recommendations of the experts interviewed. On the methodology used in other similar studies, e.g., [PERSON] and [PERSON] [18], for the practical use of the method under development, the final list of indicators should be as compact as possible while including the most critical indicators. Therefore, the last step was to reduce the list of indicators by removing those that, according to the results, had a shallow contribution to overall sustainability. At this level, it was decided to remove the indicators with a weight lower than 0.2% from the list. The reasoning for this cut-off rule comes from analysing the abovementioned BSA methods. The lowest weight in BREEAM is 0.4%, 0.9% in LEED, and 0.2% in HBSATool-PT.  
Therefore, a list considering only the indicators that contributed 0.2% or more to the overall sustainability level was proposed, which meant that the list presented in Table 2 was reduced to 48 indicators. In this process, the following indicators were excluded from the final list: Layout optimisation; Reuse of previously built or contaminated areas; Use of native plants; Heat Island effect; Visual comfort; Commissioning; Proper selection of furniture; Education of occupants; and Satisfaction surveys. Using the AHP method again, the weight of the final list of indicators was calculated.