Plus energy building: Operational definition and assessment

Considering the amount of existing buildings, decarbonizing the building stock requires new buildings designed to reach the highest performance. The nearly-Zero Energy Buildings (nZEB) standard needs to be overtaken by Plus Energy Buildings (PEB) that presents the potential to produce more energy than the consumption over a specific period. Several studies investigated the potential of a building to achieve a plus energy balance, however, there is still a lack of a comprehensive and shared framework for designing and assessing the performance of a PEB. To cope with this issue, the authors identified a series of key aspects that needs to be stated in a consistent framework for PEB, and in particular: i) the balance contributions, ii) the physical boundaries, iii) the time span for the balance assessment, iv) the metrics for evaluating PEBs, v) the approach for evaluating load matching and grid interaction, vi) Indoor Environmental Quality and user satisfaction as added values of a PEB. The authors performed a comprehensive review identifying 82 papers dealing with PEB and deducing how the key aspects have been addressed. The literature overview provides the background for proposing an approach for the PEB definition and to introduce an operational assessment focused on providing the main statements focusing on PEB performance evaluation both during the design and operative phase.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Given the significant number of existing buildings, achieving decarbonization of the building stock requires the development of new buildings designed to achieve optimal performance. Rather than simply aiming for nearly-Zero Energy Buildings (nZEB), the focus should be on Plus Energy Buildings (PEB) that have the potential to generate more energy than they consume over a specific time period. While several studies have investigated the potential for achieving a plus energy balance in buildings, there is still a lack of a comprehensive and widely accepted framework for designing and assessing the performance of PEBs. In order to address this issue, the authors have identified a series of key aspects that should be included in a consistent framework for PEBs, including factors such as balance contributions, physical boundaries, time span for balance assessment, metrics for evaluating PEBs, approaches for evaluating load matching and grid interaction, as well as the importance of Indoor Environmental Quality and user satisfaction as additional values of PEBs. By conducting a thorough review of existing literature on PEBs, the authors have laid the groundwork for proposing an approach to define PEBs and introduce an operational assessment focused on evaluating PEB performance during both the design and operational phases.