The construction industry is one of the largest energy-consuming and carbon-emitting sectors, leading to significant environmental consequences. Despite numerous initiatives and policies aimed at achieving energy efficiency and decarbonization, implementation strategies and tools face several challenges. This study explores the evolution of building energy efficiency strategies, alongside their analytical tools, examining their interconnections to identify gaps. An integrated methodology that combines bibliometric and scoping analyses was utilized within a systematic framework to identify influential strategies and tools and to examine their thematic evolution. This study makes several key contributions: it identifies eight clusters of strategies and five functionalities of analytical tools. Additionally, eight challenges and gaps were pinpointed, and nine future research directions were proposed to enhance building energy efficiency.
In recent years, decarbonisation, electrification, and the increasing integration of variable renewable energy sources have intensified the need for demand-side flexibility in low-carbon electricity systems. While industry and commerce are widely recognised as holding substantial flexibility potential, their ability to mobilise this potential varies considerably across organisational and sectoral contexts. Existing research has primarily approached this flexibility as a techno-economic optimisation problem, while less attention has been devoted to the organisational and institutional conditions required to translate technical flexibility into active participation in flexibility markets. This article develops a conceptual framework for understanding organisational demand-side flexibility through the concept of flexibility capital. Building on socio-technical perspectives and demand response research, the article conceptualises flexibility as an organisational capability shaped by technical possibilities, organisational routines, financial resources, digital infrastructures, and institutional conditions. The framework is illustrated through interview and survey material from Norwegian organisations across commercial, industrial, agricultural, and public sectors. The findings show that technical flexibility potential does not automatically translate into actionable flexibility capability. Organisations frequently identify flexibility opportunities such as storage, buffering, and energy management systems, but their ability to mobilise these opportunities is constrained by operational continuity, investment costs, fragmented responsibilities, and limited organisational capacity. The article argues that flexibility is socially and institutionally organised rather than solely technically determined. By extending the concept of flexibility capital from households to organisational contexts, the framework contributes to research on demand-side flexibility, organisational capability, and flexibility justice in future low-carbon electricity systems.
The objective of this study was to evaluate the thermal effectiveness of a prototype air-to-water heat exchanger. The system was installed in a shallow aquifer in a coastal region, characterized by a sandy medium with a documented groundwater flow velocity of 0.19 ± 0.01 m/s, operating under a hot and humid climate. The AWHE, constructed (horizontal type), has 11 m of straight sections of polyvinyl chloride (PVC) pipe. The thermohydraulic aspects of the heat exchanger were evaluated using the Number of Heat Transfer Units-Effectiveness (NTU-ε) method. The results of this study show that the temperature of the air circulating through the exchanger was reduced by between 3.02 and 7.94 °C, values higher than those obtained in similar studies with Earth-to-Air Heat Exchangers. However, the analysis is limited to short-term thermohydraulic performance in steady state. Future research is required to validate long-term performance values and the system's response to seasonal changes in aquifer temperature. High values were achieved the temperature drop per unit length in the present prototype is 1.03 °C/m, resulting in thermal effectiveness ranging from 87 to 96
Occupant behavior plays a critical role in shaping building energy consumption, yet it is often represented in energy simulations using simplified or standardized schedules. While recent studies have advanced the characterization of occupant behavior, the integration of realistic behavioral patterns into dynamic simulation environments remains limited. This study proposes a real-time co-simulation framework that integrates Rhino-Grasshopper, Python, and agent-based modeling (ABM) to dynamically represent occupant schedules, behavioral rules, and interactions with building systems without extensive preprocessing of training data. Due to the lack of context-specific occupancy data, empirically derived occupancy schedules were developed for office spaces in Jordanian universities using survey-based data and cluster analysis, resulting in nine distinct behavioral profiles across different age groups. The numerical implementation was verified through controlled scenario testing, in which the building geometry, envelope, weather data, HVAC representation, and other physical parameters were held constant while only occupancy-related inputs were varied. Because temporally matched measured energy data were unavailable for the modeled office zones, formal calibration according to ASHRAE Guideline 14 and FEMP Option D was not claimed. Instead, the plausibility of the baseline results was assessed through structured contextual benchmarking against independent local and international studies with comparable building functions, climatic conditions, energy boundaries, and performance indicators. The standardized baseline simulations produced modeled annual Energy Use Intensity values of 133.10 and 113.43 kWh m⁻2 yr⁻1 for Offices A and B, respectively, whereas the empirically derived occupant profiles produced EUI values of 342.36–514.12 and 289.20–425.15 kWh m⁻2 yr⁻1, respectively. These findings highlight the importance of integrating realistic occupancy behavior into dynamic energy simulations to improve the representation of occupancy-driven variability in energy-performance assessment in educational office buildings. The proposed framework provides a scalable and behavior-aware approach for advancing occupant-centric energy modeling.
