Towards realizing life cycle net-zero energy/emissions (LCNZE) buildings: A systematic literature review

In recent decades, the growing recognition of embodied energy and associated emissions in buildings has increased interest in life cycle assessment of buildings. The concept of net-zero operational energy buildings is now evolving into the more holistic idea of life cycle net-zero energy/emissions (LCNZE) buildings, where on-site renewable energy offsets not only operational demands but also the embodied impacts throughout the building's life cycle. This study aims to systematically review research published over the past twelve years, along with relevant policies in developed countries, to identify key advancements and knowledge gaps in the pursuit of LCNZE buildings. Given the limited availability of systematic literature reviews in this area, the novelty of this research lies in its comprehensive and structured synthesis of current knowledge and gaps, providing stakeholders, policymakers, and researchers with an improved understanding of the practices, actions, and research needed to support the transition toward a decarbonised building sector. The findings indicate that, despite a recent increase in research on LCNZE buildings, a substantial gap remains concerning how buildings can achieve a net-zero energy/emissions balance from a life cycle perspective, as well as which passive, active, and renewable measures are necessary to ensure this outcome. Future studies should comprehensively analyse the feasibility of achieving LCNZE buildings by addressing all life cycle stages (including end-of-life), considering the impact of building lifespan and its extension, climate dynamics, and employing dynamic life cycle assessments that account for variations and future improvements in material production and energy supply. Additionally, research should explore the potential of artificial intelligence, either independently or in combination with other data-driven approaches (e.g., BIM, optimisation), to support and facilitate the realisation of LCNZE buildings. From a policy perspective, while some European countries have recently introduced mandatory requirements and limit values to reduce life cycle CO 2 emissions, particularly for new buildings, it is essential to expand these requirements to include the retrofitting of existing buildings; moreover, greater harmonisation across national policies is necessary to ensure comparability and coherence. • The study provides a comprehensive synthesis toward building stock decarbonization. • 113 research articles and relevant policies were systematically reviewed. • It focuses on realizing buildings with a net-zero energy/emission balance over the life cycle. • The study identifies the potential of passive, active, and renewable measures to support this target. • Data-driven advancements and policy developments supporting this target are also highlighted.