The deficiency of the thermal performance of contemporary buildings in Egypt, with its different climatic design regions, lead to poor thermal comfort for buildings' users. This is probably caused by designs that neglect adopting the Environmental techniques and strategies in. The problem is that there are no clear reasons for this deficiency. This research aims to evaluate the application of passive thermal comfort strategies in buildings' design within the largest Egyptian climatic design region, namely (the desert region). In addition, it tries to identify the causes behind the deterioration in the thermal performance of contemporary Egyptian buildings across this region. The research employs a mixed methodology that includes analytical and investigative approaches. In the analytical part, the climatic data for (Minya) city (the representative city of the desert region) are analyzed and the most effective strategies in achieving thermal comfort within the region are identified. These effective strategies are the basis upon which the investigative part of the research is based. As for the investigative part of the methodology, questionnaire technique is adopted to collect data from local architects and experts with various qualifications and professional experiences. They are asked to assess their knowledge with effective passive strategies and their usage in design, as well as, define the constrains behind non-implementation.