ACEEE’s Pathway to Zero project supports states and local jurisdictions in adopting and implementing residential energy codes that significantly lower residents’ energy bills, reduce water use and air pollution, and improve comfort, health, and affordability.
For decades, the International Energy Conservation Code has been the leading model for residential building energy codes, but today many leading jurisdictions are seeking more advanced options. The Pathway to Zero project provides a path forward, drawing from experts and codes in leading states. It sets out a three-step process to move codes to net-zero energy use.
Three forward-looking codes for state and local governments to reach their goals
The project is developing three distinct amendment packages to the International Energy Conservation Code. These options will be available for state and local adoption and for use by programs promoting voluntary improvements beyond base codes:
- Step One - Efficient: A practical first step inspired by the ENERGY STAR program and the Zero Energy Ready Home program, which has successfully certified over 140,000 homes across the United States as of the end of 2025. View the Efficient Home code.
- Step Two - Advanced: A comprehensive package promoting very high levels of energy efficiency, incorporating elements from Passive House standards and leading state codes. View the Advanced code.
- Step Three - Net-Zero: An advanced package that combines the highest tier of efficiency with renewable energy integration so that over the course of a year the home produces as much energy as it uses. Forthcoming in September 2026.
To support all three codes, amendments to IECC chapters 2 (Definitions) and 6 (Referenced Standards) are also available. View the amendments to chapters 2 and 6.
Support for adoption and effective implementation
In addition to developing these code amendments, the project will facilitate their adoption and effective implementation. This will entail producing supporting resources and providing technical assistance to states, local jurisdictions, and utilities seeking to leverage the project’s work. The supporting resources will include a user’s manual to explain the requirements for all three codes and accompanying economic analyses.
Partners
The Pathway to Zero codes are being developed by a coalition comprising ACEEE and the states of California, Colorado, Maryland, Massachusetts, New York, and Washington, as well as the City of Seattle, Enterprise Community Partners, the National Association of State Energy Officials, and the New Buildings Institute.
To learn more, please contact Steve Nadel.