Omer, SiddigAlshabanat, Abdullah Nasser S2025-12-242025https://hdl.handle.net/20.500.14154/77663Efficient green buildings can potentially boost economic growth, enhance social development, and promote environmental sustainability. One of the contemporary challenges in building design is minimising greenhouse gas (GHG) emissions and energy use while delivering thermal comfort. A building environment that is unhealthy and delivers low levels of comfort in an effort to diminish emissions can be viewed as a failed project, similar to how a building with excessively high emissions while providing a quality thermal environment is considered an ethical failure. The building sector is highly significant in Saudi Arabia because of its impact on the development of other economic sectors and the complex national economy. Additionally, almost half of the total national electricity consumption in Saudi Arabia can be attributed to residential buildings. Therefore, the building sector plays a pivotal role in addressing energy and sustainability issues. One of the current megaprojects of Saudi Arabian Vision 2030 is the Saudi Public Investment Fund’s (PIF) ROSHN housing project, which covers an area of 150 million square metres across nine major cities. The first stage involves the SEDRA district in Riyadh, which will eventually have over 30,000 residential units across an area of 20 million square metres. Leveraging the advantages of green engineering solutions to improve the energy consumption and thermal comfort performance of such megaprojects without impacting their architectural values should be a national goal. Therefore, this research aims to evaluate the potential of green engineering solutions (traditional passive architectural design, energy efficiency measures, and low-carbon technology) in Saudi residential buildings to offer a balanced approach between cooling energy consumption and occupants' thermal comfort within the context of the sustainability concept. An understanding of the challenges and possibilities associated with integrating green engineering solutions into the design of Saudi residential buildings was essential to this study. Therefore, engaging with key stakeholders who could have provided valuable insights would have been beneficial. Furthermore, to maximise the outcomes, modelling and simulation of a case study involving a residential building from the SEDRA project were undertaken to achieve the aim and objectives of the current research. In light of these factors, the researcher selected a case study analysis and survey research methodology to represent a mixed-methods approach. The case study methodology consists of computer-based modelling and simulations that constitute the quantitative element, while the expert survey represents the qualitative dimension of mixed-methods research. Furthermore, to ensure that the research project generates new, valid, and reliable information, intense engagement with the theory surrounding research methodologies must be combined with a rigorous consideration of the unique requirements of the research subject. Accordingly, the findings of the literature review and the former and later methods were merged to gain comprehensive insight. As a result, and after the case study was evaluated, it was evident that the implementation of the proposed green engineering solutions, taking into account the sustainability context for this study, can scientifically enhance cooling energy performance and the thermal comfort levels of the base case building. For instance, moderate implementation, characterised by a balanced application of passive strategies aligning with existing building codes, resulted in mild reductions of up to 16% in cooling energy and 13% in discomfort hours. In contrast, high-level implementation involving advanced energy efficiency measures and full code adherence achieved notable reductions of up to 28% in cooling energy and 35% in discomfort hours. However, the integrated approach, which combines the three strategies of traditional passive design, energy efficiency measures, and renewable energy, produced the most significant results, with potential reductions of up to 49% in cooling energy load and 73% in discomfort hours.413enbuildingsgreensustainabilitySaudi Arabiaengineeringresidentialthermal comfortmodelling and simulationsThesis