ATLANTA, Georgia, United States, 6 June 2024: ASHRAE applauded the US Department of Energy for releasing a standardised, verifiable basis for defining a zero-emissions building.

According to ASHRAE, the ‘Zero Emissions Building: Part 1 Operating Emissions’ is a comprehensive set of guidelines aimed at providing a broadly accepted minimum standard for a zero-emissions building. By setting clear and measurable criteria, the definition offers a harmonised approach guiding public and private entities in transitioning the building sector towards zero greenhouse gas emissions, ASHRAE said through a Press Release.

Three ASHRAE standards referenced in the document include:

• ANSI/ASHRAE/IES Standard 90.1-2022, Energy Efficiency Standard for Sites and Buildings Except Low-Rise Residential Buildings
• ANSI/ASHRAE/IES Standard 100-2024, Energy and Emissions Building Performance Standard for Existing Buildings
• ANSI/ASHRAE Standard 228-2023, Standard Method of Evaluating Zero Net Energy and Zero Net Carbon Building Performance

Ginger Scoggins, 2023-24 President, ASHRAE, said: “ASHRAE is pleased to be recognized and have our referenced standards acknowledged as guiding tools in this significant milestone to combat climate change by decarbonizing the built environment. The national definition of a Zero Emissions Building provides a clear market signal and consistent target, supported by measurable data, to propel the building sector towards a sustainable future.”

ASHRAE said Part 1 of the definition, focusing on Operating Emissions, outlines three fundamental criteria for zero emissions buildings:

• Highly energy efficient: Buildings must demonstrate exceptional energy efficiency, placing them among the top performers in the market or achieving significant reductions in energy use, when compared to model codes.
• Free of on-site emissions from energy use: Zero emissions buildings must eliminate direct greenhouse gas emissions from on-site energy consumption.
• Powered solely from clean energy: All energy used by the building must come from carbon-free sources, whether generated on-site or procured from off-site sources.

ASHRAE said the definition includes detailed methods of measurement and verification to ensure compliance. Existing buildings will be assessed under criteria, such as ENERGY STAR scores or measured whole-building energy use intensity, while new constructions must meet stringent energy efficiency and clean energy standards.

While Part 1 of the definition focuses on operational emissions, Part 2 will address embodied carbon and refrigerant impacts, ASHRAE said. These elements are crucial in fully transitioning the building sector to zero emissions, the Society added.

According to ASHRAE, the National Definition of a Zero Emissions Building will be embedded in nearly every green building certification, adopted by leading investors and utilised in federal programmes.