School establishments have been considered the foundation of various civilizations, due to the importance of the educational process in producing future generations and shaping healthy societies. This paper aims to evaluate the thermal comfort sensation of pupils in school buildings under hostile climatic conditions in hot arid regions. The study employed the use of the post-occupancy approach with subjective assessments through questionnaires and physical measurements of the environmental physical parameters of thermal comfort: temperature, relative humidity, and air velocity as objective assessments. These measurements were in parallel with survey questionnaires that were undertaken during regular class sessions covering the hot and cold conditions of a school year, polling responses from 281 participants on their perception of the indoor climate. Finger's comfort indicators are calculated (PMV, predicted mean vote; and PPD, predicted percentage of dissatisfied people); and the actual people's clothing and metabolic rate are estimated in order to conclude the prevailing indoor thermal conditions. The investigations were carried out on three samples of school buildings in Biskra (Algeria) of different architectural styles. The study’s results revealed that the levels of temperature were the most crucial parameter that influenced the thermal sensation with an average of 35C° with a PMV of 2.48, and 15C° in winter with a PMV of -2.56, indicating more than 90% dissatisfaction. Therefore, a well-thought bioclimatic school design is needed to ensure acceptable indoors, and promote healthy and safe learning spaces, by adopting sustainable design principles and low-energy-consuming techniques.

In a typical hot arid climate, heat gains throughout the building envelope are responsible for more than 70% of the total thermal load. Furthermore, the thermal behavior of a building depends on the formal and constructive choices implemented in the envelope design. Since the envelope is exposed to outdoor conditions, it is crucial to give a major interest to the thermal characteristics of its structural components (i.e., walls, roof and windows). These elements are in charge of thermal exchanges between the building and its environment that occurs by heat transmission, thermal heat storage, solar heat gain and air infiltration. In return, implementing proper climatic responsive design strategies could potentially improve the envelope thermal performance while significantly reducing the building’s energy needs. The present study addresses the thermal behavior of the envelope under hot arid climate conditions by focusing on residential buildings. The research was conductuted in the city of Biskra (Algeria); it deals with the thermal investigation of the urban individual self-produced houses as the most widespread housing type in Ageria.  The study explores the potential of improving the climatic adaptability of the envelope while respecting the specific characteristics of this self-produced dwelling. To achieve this goal, optimization scenarios of the building envelope were examined by implementing a set of selected passive design strategies. The process of optimisation was initiated by performing a simulation using TRNSYS 17 software, followed by a sensitivity analysis of the envelope design elements relating to their material characteristics (architectural and constructive to evaluate their effect in regulating indoor air temperatures and providing comfort condition. The results demonstrate significant improvements in the thermal responsive of the envelope and a consequent decrease in indoor temperatures. Moreover, the study defines the most prominent strategies in the process of optimization of the envelope. Accordingly, using suitable constructive systems and materials for walls and roofs in addition to adequate orientation and judicious ratios of openings, while implementing insulation and exterior light colors found to be the most efficient design strategies.