ASHRAE and the International Code Council have announced the opening of a second public review period for proposed Standard 240P – Quantification of Life Cycle Greenhouse Gas Emissions of Buildings.

The draft standard is available for public comment from June 6, 2025, through July 21, 2025. Interested stakeholders can access the draft and submit comments at osr.ashrae.org.

Standard 240P is designed to establish a consistent methodology for quantifying both embodied and operational greenhouse gas (GHG) emissions over the entire life cycle of buildings and their sites. It also outlines minimum requirements for documentation of those emissions.

Major changes proposed from the first public comment draft include:

• Refined definitions for improved clarity and alignment with industry terminology
• Updated figure of life-cycle stages that are included in the system boundary
• Revised global warming potential metric, changing the default from GWP-20 to GWP-100
• Expanded guidance on quantifying embodied greenhouse gas emission.

The goal of the standard is to provide a unified platform that enables building industry professionals, government agencies and the finance and investment sectors to measure, report and act on GHG emissions in a clear and coordinated manner.

“Standard 240P is intended to bring clarity and consistency to how we evaluate embodied emissions throughout the building process,” said 2024–25 ASHRAE President M. Dennis Knight, P.E., BEMP, Fellow Life Member. “By working with the International Code Council, we are helping ensure that building professionals have practical, standardized tools for emissions accounting that align with broader industry needs.”

“This standard offers a unified framework for GHG accounting, empowering the building industry and related sectors to work from a common platform to measure and report GHG emissions transparently and across a building’s life cycle,” said Ryan Colker, executive director, Energy, Resilience & Innovation for the Code Council. “This kind of cross-sector collaboration with ASHRAE is essential to accelerating the transition to a climate-resilient future.”

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