Passive House and Title 24 Code Comparison Study

California’s 2025 Title 24 standards advance state goals for energy efficiency, electrification, and grid readiness. However, current compliance software does not always fully reflect the benefits of core Passive House (PH) strategies. This study develops a modeling crosswalk between the Passive House Planning Package (PHPP), WUFI Passive, and California’s CBECC compliance software across all 16 California climate zones, aligning key input assumptions and evaluating how each tool attributes energy savings, peak load reduction, and comfort-related performance.

The analysis compares Passive House-certified and Passive House-equivalent prototype buildings against prescriptive Title 24 baselines and includes targeted sensitivity testing focused on airtightness, thermal bridging, and heat recovery ventilation performance. Outcomes are evaluated in terms of annual energy use, peak demand, and Title 24 compliance results. The study also quantifies the effects of individual measures where feasible, documents key modeling challenges across platforms, and identifies where the tools diverge in their treatment of enclosure and ventilation strategies.

In addition, the study draws on case studies, practitioner interviews, and software review to identify modeling and documentation barriers that affect compliance outcomes and enforceability. The resulting crosswalk and recommendations are intended to improve consistency between Passive House and Title 24 assessments, reduce project rework associated with dual-modeling workflows, and better recognize high-performance enclosure and ventilation strategies within California’s existing compliance pathways.