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The term Net ZEB, Net Zero Energy Building, indicates a building connected to the energy grids. It is recognized that the sole satisfaction of an annual balance is not sufficient to fully characterize Net ZEBs and the interaction between buildings and energy grids need to be addressed. It is also recognized that different definitions are possible, in accordance with a country's political targets and specific conditions. This paper presents a consistent framework for setting Net ZEB definitions. Evaluation of the criteria in the definition framework and selection of the related options becomes a methodology to set Net ZEB definitions in a systematic way. The balance concept is central in the definition framework and two major types of balance are identified, namely the import/export balance and the load/generation balance. As compromise between the two a simplified monthly net balance is also described. Concerning the temporal energy match, two major characteristics are described to reflect a Net ZEB's ability to match its own load by on-site generation and to work beneficially with respect to the needs of the local grids. Possible indicators are presented and the concept of grid interaction flexibility is introduced as a desirable target in the building energy design. On behalf of all co-authors I would like to submit for publication in Energy and Buildings the attached paper with title named in the subject.As stated in the acknowledgements, the work presented in this paper has been largely developed in the context of the joint IEA SHC Task40/ECBCS Annex52: Towards Net Zero Energy Solar Buildings. However, we would like to remind you that the content of this paper does not represent an official position of the IEA on the topic.Furthermore, for obvious reasons of impartiality we feel an ethical duty to advise against choosing any of the participants to the mentioned Task/Annex as reviewer for this paper. A complete list of participants is available at the Task's website: http://www.iea-shc.org/about/members/task.aspx?Task=40 A list of suggested reviewers is also attached with the submission.We want to thank you in advance for your attention and kindness, and we look forward to hearing from you. With kind regards, Igor Sartori AbstractThe term Net ZEB, Net Zero Energy Building, indicates a building connected to the energy grids. It is recognized that the sole satisfaction of an annual balance is not sufficient to fully characterize Net ZEBs and the interaction between buildings and energy grids need to be addressed. It is also recognized that different definitions are possible, in accordance with a country"s political targets and specific conditions. This paper presents a consistent framework for setting Net ZEB definitions. Evaluation of the criteria in the definition framework and selection of the related options becomes a methodology to set Net ZEB definitions in a systematic way. The balance concept is central in the definition framework and two major types of balance are identified, namely the impo...

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Abstract"Net Zero Energy Building" has become a prominent wording to describe the synergy of energy efficient building and renewable energy utilization to reach a balanced energy budget over a yearly cycle. Taking into account the energy exchange with a grid infrastructure overcomes the limitations of seasonal energy storage on-site. Even though the wording "Net Zero Energy Building" focuses on the annual energy balance, large differences may occur between solution sets in the amount of grid interaction needed to reach the goal. The paper reports on the analysis of example buildings concerning the load matching and grid interaction. Indices to describe both issues are proposed and foreseen as part of a harmonized definition framework. The work is part of subtask A of the IEA