The building sector is an important stakeholder in the energy and environmental scenario of any country. It continues to grow across the world due to factors such as population growth, and economic and infrastructure development. Within the European Union, buildings account for 40% of the total energy requirements and 30% of carbon dioxide emissions. The building sector is keen to improve its sustainability standards and also to help achieve the 20-20-20 targets set by the European Union. The present work aims to design a nearly zero energy sports gymnasium building in Calolziocorte, Italy. Various sustainability techniques are applied in an integrated design project approach using ECOTECT software to undertake the energy modelling exercise. Firstly, the base-case is modelled with conventional building materials and the total energy demand is calculated. Duly considering the local climatic conditions, sustainable materials are chosen for walls, the floor, the roof, and windows and a 38% reduction is noted in the total energy demand of the building compared to the base-case. The impact of louvers as a passive design technique has also been examined on the total energy demand of the building. The monthly load/discomfort analysis is undertaken for various individual functions inside the building to identify the critical areas that consume more energy. The monthly load/discomfort analysis is performed with the proposed materials and the air infiltration rate is improved through the building envelope and 63% reduction is noted in the total energy demand of the building compared to the base-case. A solar access analysis is conducted to understand the on-site energy production and then the building net energy demand is calculated, which is reduced to 90% compared to the base-case.

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.

In high-occupancy intermittent buildings, such as mosques and theaters, it is challenging to design proper air distribution systems and HVAC (heating, ventilating, and air-conditioning) operation strategies to maintain thermal comfort at reduced energy consumption. This study investigates the thermal and energy performance of a high-occupancy intermittently operated mosque in Saudi Arabia. DesignBuilder software (version v4.7) was used for the coupled energy and computational fluid dynamics simulations. The continuous HVAC operation results indicate an annual cooling energy consumption of 181 kW · h/m², with only two under-floor air distribution system models [through-wall supply with eight diffusers at 3 m height and ceiling return (M5) and through-wall supply with 10 diffusers at 3 m height and wall return at 3 m from the ground (M6)] achieving thermal comfort with only a few cold spots in the throw areas. The intermittent operation saved 30% of the total annual energy consumption, reducing it from 181 to 127 kW · h/m², in turn, saving 35% of the total cooling energy consumption. Intermittent HVAC operation cases achieved thermal comfort, except for the four-way ceiling supply and wall return (M1). Therefore, implementing intermittent HVAC operation strategies in high-occupancy buildings significantly reduces energy consumption, while achieving thermal comfort when appropriate air distribution strategies are employed. These results provide critical guidelines for the design and operation of proper HVAC systems.