This thesis explores the factors that influence sustainable decision-making among construction contractors in Albania. The country has been a candidate for membership of the EU since 2014, and the construction sector is a pivotal part of the economy. However, it is also one of the industries that contributes the most to environmental degradation. This intensifies the urgency of adopting sustainable practices. Nevertheless, the construction sector faces several challenges to sustainable development, including limited access to sustainable materials, the lack of control by government, and financial constraints. Using a mixed-methods approach, this research combines a literature review, semi-structured interviews, and questionnaires conducted among Albanian contractors to identify the key determinants of sustainable decision-making. Results revealed that the main factors that influence contractors' decisions were cost, government regulation, material availability, client preferences, and the contractors' experiences. The lack of robust policies was identified as a major barrier, highlighting the necessity for government to establish regulatory frameworks to support sustainability. The conclusion recommends that Albanian policymakers should implement stricter sustainability regulations, allow greater availability of sustainable materials, and increase training and awareness programs for contractors following a EU standard.

The increasing generation of municipal solid waste (MSW) due to urbanization and population growth has highlighted the importance of effective Municipal solid waste management. Waste sorting plays a critical role in enhancing waste quality and boosting recycling rates, aligning with the circular economy goals of the European Union. However, despite significant waste production in cities, limited separation and recycling occur, primarily due to insufficient citizen involvement. When it comes to involving citizens in sorting household waste, there has been limited research and exploration of the waste sorting behavior of college students. Given that the majority of college students reside in student housing, the research aims to understand college students’ waste sorting behavior in student housing and recommend interventions that motivate students to engage in waste sorting.

To attain the objective, the research utilized a mixed research approach, initially employing semi-structured interviews as the qualitative method and subsequently conducting an online survey as the quantitative method. Qualitative results were derived through the application of thematic analysis and subsequently served as a basis for constructing the questionnaire survey in the subsequent quantitative phase. The factors that impact waste sorting behavior in student housing were identified and quantified in the quantitative phase by employing the partial least square structural equation modeling (PLS-SEM) method.

The results revealed that the subjective norm and perceived behavioral control directly impact students’ intentions to engage in waste sorting, which in turn, indirectly affects their waste sorting behavior. In addition, the waste sorting facilities and information publicity holds a significant influence on the students’ household waste sorting behavior.

Based on the findings, it is suggested that the intervention aimed at encouraging waste sorting among students could involve enhancing the publicity of waste sorting information by providing information prompts in the communal space within student housing and distributing information through social media. Furthermore, interventions like improving the waste sorting facilities could engage students in waste sorting. Additionally, promoting communication within the student housing community and incorporating waste sorting education into the college curriculum were also suggested as interventions to incentivize students to sort their household waste.