Zero Carbon Emission Buildings defined and decoded: A Holistic review from conceptual foundation to practical application

The building sector, along with transport and industry, accounts for the largest share of global final energy consumption and greenhouse gas emissions and is a key area for carbon reduction. For this reason, the concept of Zero Carbon Emission Buildings (ZCEB), i.e., buildings with no impact in terms of CO2 emissions at least in a certain part of their lifecycle, is attracting considerable international attention and is regarded as a pivotal solution and future pathway to achieving the objective of carbon neutrality in the built environment and to curbing global temperature rise. In this context, the present work provides a comprehensive review of the recent academic literature on ZCEB, aiming to cover research hotspots, definition clarifications, technical strategies and tools to drive its realization, in which existing challenges were analysed, and a conceptual framework was proposed. To better understand the viability and gaps in real-world zero-carbon emission practices, several representative case-studies were assessed to quantitatively compare the frequency of application of various strategies and the achievement of ZCEB goal in their respective geographical areas. The findings indicated that only slightly more than half of the cases met the established targets, which might be due to their ambitious definitions, non-optimised design strategies and/or technologies, and uncertainties in computational evaluation. The theoretical to empirical basic elements of ZCEB outlined in this review could provide guidance to researchers, policy makers, and practitioners for its further development and judicious application.