Abstract Rapid urbanization and climate change are intensifying energy demand and emissions from the built environment, making them critical components of climate-neutral and sustainable cities. To address this challenge, Net-zero energy buildings (NZEB) are widely promoted as a promising solution. However, the existing literature remains fragmented across technologies, disciplines, and performance metrics, and thus limits a comprehensive understanding of NZEB pathways and their system-level implications. This study presents a comprehensive assessment of NZEB research by integrating qualitative narrative synthesis with quantitative bibliometric analysis of 2,658 publications from 2021 to 2025. The narrative review identifies key design strategies, technological pathways, and conceptual limitations, while the bibliometric analysis systematically maps thematic evolution, research trends, and collaboration structures. The results reveal that NZEB research is predominantly centred on energy efficiency and renewable integration but remains largely component-driven, with limited emphasis on system-level design, real-world validation, and cross-domain integration. Emerging themes such as energy storage, optimization, and decarbonization indicate a transition toward more integrated approaches; however, critical gaps persist in life-cycle assessment, occupant behaviour, economic feasibility, and grid interaction. The analysis also highlights the early-stage integration of digital and data-driven methods, underscoring the need for machine learning, uncertainty-aware modelling, and risk-informed optimization to address variability in climate and demand. These findings emphasize the need to transition from isolated technological solutions toward holistic, system-oriented NZEB frameworks that enhance scalability, resilience, and climate neutrality.
Verma et al. (2026) studied this question.