# Adaptation of the SBTool for Sustainability Assessment of High School Buildings in Portugal--SAHSBT
## 2 Structure of the Methodology  
The selection of indicators was made through a process in which a specialist chose which indicators and categories should compose the SAHSBPT methodology, as well as their weights, after considering all the indicators from LEED BD + C School, BREEAM Education, SBTool for K-12 Schools, and SBToolPT-STP for Office Buildings. The SBToolPT methodology was chosen, because it allows a greater possibility for adjusting the indicators evaluated in each dimension, considering the building typology, building site, and its practicality, demonstrating greater flexibility and also reducing subjectivity, which makes it more adaptable in relation to other more rigid and extensive systems [1]. Furthermore, because the SBToolPT was developed in Portugal, it is the tool most suited to practical application in Portuguese society. The evaluation process used in the SAHSB\({}^{\text{PT}}\) methodology follows the calculation methods of SBTool\({}^{\text{PT}}\)-STP for Office Buildings, using indicators related to social, economic, and environmental aspects and comparing them with national practices [10]. Such indicators usually follow the following structure [1; 11]:  
1. Objective aspects that are intended to promote and reward the building;
2. Required elements for evaluation, in which the necessary data for the evaluation are found;
3. The life cycle phase to which the indicators apply: project phase, construction phase, or use phase;
4. Benchmarks of the indicators, corresponding to the levels of current practice and best practice;
5. Method of calculation, which provides a description of the steps and methodologies needed to quantify the performance of the building;
6. Standardization to normalize and quantify the performance level of the building in the context of the indicators according to the previously defined benchmarks;
7. Evaluation to summarize the performance level of the building at the indicator level, using the qualitative scale consisting of six levels (A+-E), which is used to communicate the result of the evaluation. The process of evaluating the sustainability of a high school building using the methodology proposed in this work, which is composed of three phases and mirrors the SBTool\({}^{\text{PT}}\) evaluation framework [1; 11]. **Phase 1:**  
The evaluation of the specific performance of each indicator includes the following steps: quantification of the indicators and their standardization. The standardization of the indicators sets a dimensionless value that demonstrates the performance of the building in relation to the benchmarks. In this process, the Diaz-Baltero equation is used [12]. \[\overline{\text{P}_{I}}=\frac{\text{P}_{I}-\text{P}_{I*}}{\text{P}_{I*}-\text {P}_{I*}} \tag{1}\]  
where \(\overline{\text{P}_{I}}\) represents the standardization value of the indicator; \(\text{P}_{I}\) represents the result of the quantification of the indicator; \(\text{P}_{I*}\) represents the value of the best practice; and \(\text{P}_{I*}\) represents the value of the conventional practice. The best practice is the value corresponding to the data originated for scientific work concerning the subject of each indicator, data produced by designers who already have some reputation in the field of sustainable construction, or data developed as a result of existing policies and standards. In the absence of references for Portugal, data from other countries was used [1; 11]. The standard practice is the minimum value acceptable to consider a building sustainable. This value is based upon the minimum levels prescribed in the regulations and requirements of the current construction or practices of construction of residential buildings in Portugal. The standardization values (X) are converted into a qualitative scale to facilitate the understanding of the results obtained. These results range between A (more sustainable) and E (less sustainable). In the qualitative scale presented, level A corresponds to the best practice and D to the standard practice, as shown in Table 1[1; 11].