The paper presents a consistent framework for defining Net Zero Energy Buildings (Net ZEBs). It addresses the need for a standardized definition due to varying national policies and conditions. The framework identifies two major balance types: import/export balance and load/generation balance, with a simplified monthly net balance as a compromise. The balance concept is central, emphasizing the need for a time-based energy match to ensure buildings can meet their own load through on-site generation and work well with local grids. The paper introduces the concept of grid interaction flexibility as a desirable target in building design. It also discusses the importance of considering embodied energy and the role of weighting systems in evaluating different energy carriers. The framework includes criteria for defining the building system boundary, weighting system, and temporal energy match characteristics. The paper highlights the need for a consistent definition that allows countries to adapt to their specific conditions, including primary energy conversion factors and energy efficiency requirements. The framework aims to provide a systematic and comprehensive approach to defining Net ZEBs, ensuring they are environmentally friendly and sustainable. The paper also discusses the challenges of defining Net ZEBs, including the need for accurate energy data and the impact of different energy supply options. The framework is intended to support the development of policies and regulations that align with national and international energy targets.The paper presents a consistent framework for defining Net Zero Energy Buildings (Net ZEBs). It addresses the need for a standardized definition due to varying national policies and conditions. The framework identifies two major balance types: import/export balance and load/generation balance, with a simplified monthly net balance as a compromise. The balance concept is central, emphasizing the need for a time-based energy match to ensure buildings can meet their own load through on-site generation and work well with local grids. The paper introduces the concept of grid interaction flexibility as a desirable target in building design. It also discusses the importance of considering embodied energy and the role of weighting systems in evaluating different energy carriers. The framework includes criteria for defining the building system boundary, weighting system, and temporal energy match characteristics. The paper highlights the need for a consistent definition that allows countries to adapt to their specific conditions, including primary energy conversion factors and energy efficiency requirements. The framework aims to provide a systematic and comprehensive approach to defining Net ZEBs, ensuring they are environmentally friendly and sustainable. The paper also discusses the challenges of defining Net ZEBs, including the need for accurate energy data and the impact of different energy supply options. The framework is intended to support the development of policies and regulations that align with national and international energy targets.