The application of renewable energy has been an integral part of the sustainability drive in the building sector and solar photovoltaic (PV) is one of the most effective technologies in this respect. The present study aims to investigate the prospects of solar PV in residential buildings in the hot–humid climatic conditions. The study discusses the utilization of building roofs for the application of PV in terms of potential hurdles and utilization factor (UF). Technical performance of PV systems has also been investigated in terms of power output as well as the energy saved as a result of the shading impact of panels for two types of residential units, apartments and villas. Investigation of 70 sample residential buildings reveals the average UF of 0.21 and 0.28 for apartments and villas, respectively. For the case study of apartment and villa residential units, roof UF has been found to be 13% and 15% with a respective PV output of 6079 kWh/year and 6162 kWh/year. Potential PV output at the city level has also been estimated. A sensitivity analysis has been conducted to evaluate the impact of various cost and design parameters on the viability of PV systems.

Mosques, places of worship for Muslims, are used for five intermittent prayer periods a day with a duration of between 45 and 60 min each. Their unique function and pattern of operation result in unique energy consumption and demand. Although mosques can be characterized as high-occupancy buildings, the thermal design of the exterior envelope can play a major role in their thermal and energy performance particularly in hot-humid climates. The objective of this study is to investigate energy performance and potential energy savings associated with influencing envelope design parameters under hot-humid climatic conditions. The results revealed that envelope parameters such as wall and roof thermal resistance, and air leakage rate are major determinants of mosque energy performance and subsequently, considerable savings can be achieved when properly considered. Recommendations for envelope thermal design are presented to provide architects, engineers, planners, community developers and mosque operators with necessary guidelines for improving mosque energy performance.

This study comprehensively evaluates the energy-saving potential and visual comfort aspects of electrochromic (EC) smart windows in a hot-humid climate office building. Using an advanced building simulation tool, EC windows are compared to conventional low-E glazed windows, considering two control triggers: daylighting level and glare control. The primary objective is to determine energy savings achievable with EC windows while addressing visual comfort. Detailed analysis of the building’s energy performance and indoor environment is conducted. Results show significant energy savings of 23% with EC windows using daylighting control but limited visual comfort in some zones. Conversely, EC windows with glare control achieve 17% energy savings while maintaining visual comfort throughout the building. These findings highlight the potential of EC windows with glare control in saving energy and maintaining visual comfort in hot-humid office buildings. Further research is needed to optimize performance for different building types and climates. In conclusion, this study provides insights into energy-saving capabilities and visual comfort considerations with EC smart windows, emphasizing the importance of appropriate control triggers for maximizing energy savings and occupant comfort. Future investigations should explore EC window performance across diverse building typologies and climates to enhance the benefits of this innovative technology.

Modular construction is becoming famous for buildings because it allows a high degree of prefabrication, with individual modules easily transported and installed. Building envelope optimization is vital as it protects buildings from undesirable external environments by expressly preventing the incursion of outside elements. This research uses a systematic literature review to appraise the characteristics of modular envelope panels, focusing on hygrothermal and energy performance. A total of 265 articles were subjected to rigorous filtering and screening measures. The findings reveal notable inconsistencies in modular envelope terminologies and a lack of consistent performance measures, which present significant challenges for research and development efforts. Furthermore, the results indicate a predominant focus on hygrothermal and energy performance in existing studies, with limited attention to environmental impacts and other performance factors. Moreover, the existing literature primarily addresses modular envelope solutions in temperate climates, offering inadequate information for hot and hot–humid climate contexts. To address these gaps, this study proposes categorizing modular envelope panels into four distinct categories: active, passive, smart, and green/vegetated wall panels. These findings will benefit researchers, architects, building envelope designers, policymakers, and organizations developing building performance-related assessment ratings, standards, and codes. The study suggests adopting the categorization of modular envelope panels provided in this study and developing modular panels suitable for hot and humid climates to fill the existing knowledge gap.

Air leakage is an essential factor contributing to overall building performance. It plays a major role in determining energy consumption in harsh climates, particularly in residential buildings, as it represents a significant component of the envelope-induced thermal load. In centrally air-conditioned houses, the HVAC system can substantially alter the pressure distribution across the exterior envelope, reforming the air leakage behavior. Nonetheless, limited information is available to characterize and better understand such behavior to accurately predict building performance and energy consumption toward meeting the emerging requirements for sustainable buildings. This study experimentally investigated the air leakage behavior of a selected sample of centrally air-conditioned typical single-family detached houses in Saudi Arabia. The air leakage behavior was investigated by measuring the overall airtightness and the contribution of the different air leakage paths using the viable method of the blower door test (BDT). The air leakage rate was then calculated using the measured induced pressure across the envelope during the HVAC system operation. Results indicated that the air leakage behavior is significantly altered by the pressurization induced by the central HVAC system, eliminating air infiltration and producing an outward airflow across the entire envelope. The study addresses a current challenge in characterizing envelope air leakage behavior for a common type of house and, thus, would indirectly contribute to more accurate thermal and energy performance assessments. Several aspects were highlighted for consideration when defining the contribution of air leakage to energy consumption prediction and studying air leakage behavior in other types of buildings.

Soils in Saudi Arabia are emerging as potential sustainable building materials, a notion central to this study. The research is crucial for advancing construction practices in arid areas by enhancing soil thermal properties through stabilization. Focusing on Hejaz region soils, the study evaluates the impact of stabilizers such as cement, lime, and cement kiln dust (CKD) on their thermal behavior. This investigation, using two specific soil types designated as Soil A and Soil B, varied the concentration of additives from 0% to 15% over a 12-week duration. Employing a TLS-100 for thermal measurements, it was found that Soil A, with a 12.5% cement concentration, showed a significant 164.54% increase in thermal conductivity. When treated with 2.5% lime, Soil A reached a thermal conductivity of 0.555 W/(m·K), whereas Soil B exhibited a 53.00% decrease under similar lime concentration, reflecting diverse soil responses. Notably, a 15% CKD application in Soil A led to an astounding 213.55% rise in thermal conductivity, with Soil B recording an 82.7% increase. The findings emphasize the substantial influence of soil stabilization in improving the thermal characteristics of Hejaz soils, especially with cement and CKD, and, to a varying extent. This study is pivotal in identifying precise, soil-specific stabilization methods in Saudi Arabia’s Hejaz region, essential for developing sustainable engineering applications and optimizing construction materials for better thermal efficiency.