A Market Based Definition of Hybrid Net Zero Energy Buildings Emphasizing Renewable Energy Development in Iran’s Agricultural Buildings

In recent years, the concept of Net Zero Energy Buildings (NZEBs) has emerged as a central pillar of decarburization policies and sustainable development strategies. However, most existing definitions are primarily based on annual energy balance and a strong reliance on on-site renewable energy generation. This approach shows limited practical applicability across diverse climatic conditions, transitioning energy systems, and urban contexts with constrained installation capacity, such as many regions of Iran. To address these limitations, the present study identifies existing conceptual gaps through a critical review of the literature and proposes an innovative definition—termed the Hybrid Net Zero Energy Building (Hybrid NZEB)—by integrating market-based mechanisms with technical energy approaches.Within the proposed framework, net-zero status can be achieved through an optimal and weighted combination of three energy sources: on-site renewable energy generation, procurement of Renewable Energy Certificates (REC), and the purchase or generation of Energy Saving Certificates (ESC). Beyond energy quantity, the proposed definition explicitly incorporates energy quality (exergy), temporal value of energy consumption, climatic adjustment factors, and grid value coefficients into the energy balance calculations. Consequently, the building is conceptualized not as an isolated entity but as an active component of an integrated energy–market ecosystem.A critical assessment of existing NZEB literature indicates that the proposed Hybrid NZEB framework not only overcomes key shortcomings of conventional NZEB definitions but also enhances renewable energy markets, stimulates decentralized investment, and increases the economic value of energy efficiency measures. Furthermore, the application of the proposed methodology to a representative poultry farm case study demonstrates that the combined utilization of on-site renewable energy production, renewable energy certificates, and energy saving certificates increases the annual effective energy to 193.6 MWh, exceeding the facility’s annual energy demand of 180 MWh. The resulting positive net energy balance of 13.6 MWh confirms that the examined poultry unit qualifies as a Hybrid NZEB under the proposed definition.