The ASHRAE Standard 90.1 Performance Rating Method (PRM) has long been a cornerstone of performance based energy compliance, enabling design flexibility while supporting beyond-code programs, incentives, and policy goals. However, the introduction and expansion of the “stable baseline” framework - particularly fixed baseline system mappings and Building Performance Factors (BPFs) - have fundamentally altered how PRM functions in practice. While intended to simplify modeling and standardize performance targets, these changes have introduced significant challenges for real-world projects and practitioners.

In 2024, a coalition of practicing energy modelers submitted a Continuous Maintenance Proposal (CMP) to ASHRAE SSPC 90.1 documenting widespread issues with the current PRM framework. This effort was supported by a national practitioner survey and a broad set of real project case studies spanning multifamily residential, healthcare, laboratories, higher education, manufacturing, data centers, warehouses, and civic buildings. The results revealed a recurring pattern: projects that are prescriptively compliant - and often compliant under the Energy Cost Budget (ECB) method - frequently fail PRM by substantial margins. These failures are especially pronounced for electrified buildings, facilities with high process or unregulated loads, and building types that are poorly represented by existing prototype models and BPF categories.

This panel session will review the technical and methodological origins of the PRM stable baseline, summarize key findings from practitioner feedback and case studies, and discuss the implications for design teams, owners, and authorities having jurisdiction. Panelists will explore how current PRM outcomes influence system selection, electrification strategies, project affordability, and the perceived credibility of energy modeling as a design and compliance tool.

The discussion will also focus on potential paths forward for the industry, including short-term mitigation strategies and longer-term structural changes to PRM. Topics will include alignment between prescriptive and performance pathways, treatment of unregulated and process loads, baseline fuel selection, transparency and validation of prototype modeling, and the future role of ECB style system-to-system comparisons. The panel will conclude with a forward-looking discussion on what the next generation of ASHRAE 90.1 energy modeling could look like - balancing rigor, fairness, transparency, and real-world applicability.

The intent of this session is not to reduce code stringency, but to foster an informed, practitioner-driven dialogue on how performance based compliance can continue to support high performance and cost effective building design.