California implemented its updated 2025 Building Energy Efficiency Standards (Title 24) on January 1, 2026. These standards require heat pumps for both space heating and water heating in all new residential buildings. The update introduces stricter HVAC control requirements, shifts HERS verification to the new ECC compliance framework, and applies expanded refrigerant and efficiency mandates. These measures impact installers, manufacturers, and training programs statewide.
Background
California's triennial Building Energy Efficiency Standards are designed to reduce energy consumption and greenhouse gas emissions. The 2025 update was adopted on September 11, 2024, and takes effect January 1, 2026. It promotes efficient electric heat pumps for new single-family, multifamily, and select nonresidential buildings, supporting state decarbonization objectives1Energy Commission Adopts Updated Building Standards Expanding Requirements for Heat Pumps and Electric-Ready Buildings.
The updated Energy Code now requires simultaneous application of heat pumps for space conditioning and water heating, establishing a dual-heat-pump baseline. This replaces the prior allowance for single-heat-pump systems2California Energy Commission. A six-year moratorium on residential code updates (AB 130 / AB 306) ensures code stability through mid-2031, unless exceptions for safety or emergencies arise3APPENDIX B2.
Details
New residential HVAC systems must meet minimum efficiency standards. Unitary air-to-air heat pumps with capacities up to 65,000 Btu/h must achieve specified minimum SEER ratings-typically 14.0 SEER for split systems-and comply with all referenced appliance efficiency regulations4Energy Code Ace - Cooling Equipment.
Updated control requirements under Title 24 JA18 mandate standardized, auditable control logic for HVAC installations starting January 1, 2026. Carrier submitted pre-certified control sequences for its i-Vu building automation system, facilitating compliance and system commissioning5Carrier Aims to Ease California’s 2026 HVAC Overhaul with Pre-Certified Control Sequences | ACHR News.
Verification and testing now follow the new Energy Code Compliance (ECC) program, replacing HERS I protocols. ECC continues requirements for duct leakage, airflow, and refrigerant charge testing, while updating terminology, training, and registry frameworks to meet the 2025 code cycle6HERS → ECC: What California’s 2026 Change Means for Duct Testers – Vent Cap Systems.
Refrigerant policies are more stringent. Under state and EPA rules, residential and light commercial heat pumps installed after January 1, 2026, must use refrigerants with a global warming potential (GWP) of 700 or lower, superseding the prior 750 GWP state limit7ENERGY RESEARCH AND DEVELOPMENT DIVISION.
An ENERGY STAR exemption accommodates heat pumps complying with the 2025 code by allowing exceptions to standard cooling sizing limits. This adjustment addresses conflicts between federal sizing rules and California's minimum heating capacity requirements, exempting certain design checklist items for designers and raters8Blueprint Newsletter: Winter 2026 | California Energy Commission.
Outlook
Contractors and training organizations must adapt to Title 24 JA18 control mandates and ECC compliance protocols shortly. With residential code requirements fixed through 2031, manufacturers and installers have a clear framework for planning. The transition period will emphasize refrigerant-efficient heat pump technology and skill development in audit-ready controls and compliance testing.
