Last month, the California Energy Commission adopted the 2025 Building Energy Efficiency Standards (Energy Code). These updates will contribute to California’s efforts to decarbonize its buildings as well as providing more than $4.8 billion in estimated statewide energy cost savings over 30 years. The new building code goes into effect on January 1, 2026, and remains in effect through Dec 31, 2028.
One terminology change to note, across both the residential and nonresidential sectors, is the replacement of the Time Dependent Valuation (TDV) metric with a new term, Long-Term System Cost (LSC). Just as with TDV in the previous code cycle, this is the CEC's projected valuation of costs to California’s energy systems over a period of 30 years.
This article covers:
Single Family and Multi-Family Energy Code Overview
The 2025 Standards focus on strengthening heat pump requirements for space and water heating with additional focus on envelope and pool heating. Single family new construction highlights include:
Extending the prescriptive standard for heat pumps for space heating to all climate zones
Requiring controls to improve performance of heat pumps, including defrost timers and limits on supplementary heat to 35°F and below
Prescriptively requiring heat pump water heaters in all climate zones
Adjusting requirements for high-performance windows and walls
Establishing new mandatory options that encourage heat pumps for heating newly constructed swimming pools and newly installed pool heaters for existing pools
Multi-family new construction highlights include:
Introducing a prescriptive requirement for sizing water pipes according to California Plumbing Code Appendix M for central domestic hot water (DHW) systems
Prescriptively requiring a heat pump for water heating equipment serving individual dwelling units in all climate zones
Mandating electric readiness for central gas water heating systems
Strengthening envelope provisions including cool roof, wall and fenestration performance
Energy Code Ace is conducting training sessions on what’s new in single family and multi-family residential 2025 standards, with upcoming webinars on November 5, 2024 and December 3, 2024.
Non-Residential Energy Code Overview
The 2025 Energy Code continues to focus on advancing electrification, strongly encouraging heat pumps for more building types and applications and updating photovoltaic and battery energy storage system requirements. Updates include:
Introducing prescriptive heat pump standards for select nonresidential building types (when replacing single-zone rooftop units less than 65,000 Btu/h)
Prescriptively requiring multizone HVAC heat pumps in most climate zones for office and school building types
Prescriptively requiring heat pump water heaters in schools greater than 25,000 ft2 for most climate zones (CZs 2-15)
Replacing end-of-life rooftop heating, ventilation, and air-conditioning (HVAC) units of a certain size with heat pumps, for existing retail, schools, offices and libraries, or with an air conditioner with additional efficiency measures
Establishing electric-ready requirements for commercial kitchens
Updating solar and storage standards for assembly buildings, including religious worship, sport, and recreation buildings
Energy Code Ace is conducting training sessions on what’s new in the nonresidential 2025 Energy Code, with upcoming webinars on November 6, 2024, December 4, 2024, and January 15, 2025.
Chart of Changes to the Energy Code
A detailed chart of changes to the 2025 Energy Code are outlined below based on the following factors:
Occupancy Type: Single Family (SF), Multifamily (MF), or Nonresidential (NR)
Event Type: New Construction (New) or Additions & Alterations
Code Reference: Where you can find this change in the energy code
Topic: What is affected by this change
More Information for the 2025 Code Cycle
To learn more about timing concerns, review our article here.
As more information is available, we will update this page. Expected updates include recommended policy options and overall cost-effectiveness study results.