Washington State proposes new Energy Rating Index compliance path for 2024 building code

On May 30, 2025, the Building Code Council convened to discuss significant updates to the Washington State Energy Code, particularly the introduction of an Energy Rating Index (ERI) compliance pathway. This proposed addition aims to enhance energy efficiency standards for new homes, aligning with both state and federal energy goals.

The ERI is a numerical representation of a home's energy efficiency, typically ranging from 0 to 100, where lower scores indicate better efficiency. The proposal seeks to establish a compliance path that allows builders to demonstrate energy efficiency through ERI scores, which could potentially streamline the process and encourage the adoption of energy-efficient practices. This approach is particularly relevant as it aligns with federal incentives, such as the 45L tax credit, which rewards energy-efficient construction.

During the meeting, participants discussed the feasibility and implications of integrating the ERI pathway into the existing code framework. Key considerations included ensuring that the new compliance path does not create disparities in energy efficiency standards compared to other pathways. The council emphasized the importance of maintaining a balance between complexity and clarity in the code, aiming to avoid confusion among builders and officials.

The discussion also highlighted the role of HERS raters—certified professionals who assess energy efficiency—who would be involved in the ERI rating process. Their expertise is expected to enhance the overall efficiency outcomes of new constructions, as they can identify potential improvements early in the building process.

While the proposal is still in its early stages, the council is keen to gather feedback from stakeholders to refine the ERI targets and ensure they align with the broader goals of the 2024 Washington State Energy Code. The council's approach is to first establish a foundational understanding of current energy efficiency levels before setting ambitious targets for future compliance.

In conclusion, the introduction of the ERI compliance pathway represents a significant step towards improving energy efficiency in Washington's residential construction. As discussions continue, the Building Code Council aims to finalize the proposal, ensuring it meets the needs of builders while contributing to the state's energy reduction goals. Stakeholders are encouraged to provide input as the council navigates the complexities of this important initiative.