The building envelope is the first barrier to protect against external climatic variations. Generally, it consists of two types of walls: opaque walls (walls and roof) and transparent walls (Windows). The design characteristics of the enclosure strongly affect the occupants' thermal comfort, as well as the building energy consumption. The constructive choices relating to structural elements, in particular, walls, roofing and openings are generally considered in the thermal exchanges between the building and its environment. In the present study, which is based on experimental analysis in the self-generated residential sector in Biskra (Algeria), where a warm and arid climate predominates, we aim to evaluate the thermal impact of certain architectural and constructive parameters that are specific to residential habitat self-produced in Biskra. This paper summarizes the main results obtained from an in situ measurement campaign that evaluated the essential parameters of thermal comfort such as ambient and surface temperature, air velocity, and humidity. These parameters were used as indicators to measure the impact of the envelope material characteristics on its climatic adaptability. This paper also presents some recommendations for optimizing the choice of building materials specific to the self-produced residential in order to improve its thermal performance while preserving the essentials of its specificities.

The rural habitat in the Aures region is an excellent example on vernacular and human architecture. It reflects how inhabitants of this region responded to their requirements in an ingenious way and how local builders have succeeded to respond to challenges of climate, building materials and cultural expectations despite the particularly harsh environmental conditions of the Aures. The aim of this study is to determine the strategies used in vernacular constructions to deal with the severe climatic conditions that prevail in the Aures region. Precisely, rural dwellings in Ain Zaatout village (Beni Ferah) were studied to emphasize the importance of the architectural properties of the traditional houses in terms of thermal performance and climatic adaptability. In this regard, an extensive literature review was carried out on previous studies that investigated the Aures settlements. Accordingly, a comprehensive knowledge on typical Aurassien village and various data including spatial organisation, architectural characteristics and construction materials and techniques have been gathered. Based on this background, a qualitative analysis supported by field measurements was conducted. Then, two representative houses were selected as case studies for monitoring comfort parameters in summer period. Finally, the traditional and contemporary houses were compared in terms of their thermal performance. Through this study, the most frequently used strategies and their effectiveness were derived. The results indicate that vernacular rural habitat in the Aurassien villages is creatively adapted to the environmental conditions and uses various climate responsive strategies. The study additionally reveals that vernacular constructions in the Aures are more adapted to the climate constraints and social needs than contemporary residential buildings. These results were confirmed by hydrothermal values where main indoor temperature in a traditional rural house was less than external values by 3 °C and more humidified, while in modern house indoor temperature records were more than the exterior by 1°C. Thus, vernacular climatic responsive strategies must be considered as a reference for nowadays environmental issues in rural areas. Moreover, they can be feasible for contemporary buildings and, consequently, they could contribute greatly towards improving indoor thermal comfort whilst reducing buildings energy demand.

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.

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