As of January 1, 2026, California has officially implemented the 2025 Energy Code, bringing one of the most significant administrative shifts in years for the building industry. For over a decade, builders and contractors have relied on the Home Energy Rating System (HERS) to verify compliance with Title 24.
However, under the new code cycle, the familiar HERS terminology is being replaced by the Energy Code Compliance (ECC) program. ECC isn’t just a new acronym; it’s a move to relocate field verification requirements directly into Title 24 of the California Code of Regulations to improve oversight and performance.
The 2026 Shift: Why HERS is Evolving
Change #1: The Administrative Move to the ECC Portal
The most immediate change for San Diego builders is how and where their compliance data is handled. Historically, HERS regulations lived under a separate section of the California Code of Regulations (Title 20). Now, the ECC Program is housed directly within the Building Energy Efficiency Standards (Title 24, Part 1).
What this means for your project:
- Digital-First Registry: All verification data is now managed through approved ECC-Providers—organizations authorized to oversee compliance documentation—and digital registries, such as CHEERS (California Home Energy Efficiency Rating System). These electronic systems are designed to be more integrated with local building departments.
- Zero-Tolerance for Data Errors: Because the registry is now tied more closely to the permitting process, initial data entry must be 100% accurate. In the past, minor clerical errors could often be fixed at the final inspection. Under ECC, a data mismatch can trigger a “red flag” in the system, potentially delaying your occupancy permit.
- Compliance forms, formerly CF2Rs and CF3Rs, now use ECC terms for projects permitted under the 2025 code.
Merging this paperwork with the construction code requires stronger coordination between the builder and the rater from day one.
Change #2: The Prescriptive Baseline for Heat Pumps
The primary tool in the 2025 Energy Code’s push for decarbonization is the Heat Pump. Under ECC, heat pumps are now the baseline for space and water heating in most new homes.
What this means for your project:
- Heat Pump Water Heaters (HPWH): In most climate zones—including here in San Diego—installing a heat pump water heater (an appliance that uses electricity to move heat to heat water efficiently) is now required. If you choose to stick with a traditional gas-fired system, you may be required to compensate for that ‘energy penalty’—the extra energy use—elsewhere in the building envelope to meet your overall energy budget.
- Space Heating Baselines: For new single-family homes, the code now encourages or assumes heat pumps for space conditioning.
- Even if gas appliances are used, you must meet broader electric-ready requirements by providing branch circuits and panel space for a future all-electric upgrade.
At Grizzly HERS, we specialize in verifying these high-efficiency systems to ensure they perform exactly as intended during the design phase.
Change #3: Mandatory Field Verification (FV&DT) Expansion
The most technical shift in the ECC program involves Field Verification and Diagnostic Testing (FV&DT). The 2025 cycle hasn’t just changed the rater’s name; it has also tightened the tolerances for the tests themselves.
What this means for your project:
- The refrigerant charge ‘weigh-in’ method is updated. Installers can’t rely solely on FID; the ECC-Rater must now verify system performance more rigorously.
- Quality Insulation Installation (QII) verification is now often required. Because QII needs several inspections, you must coordinate with your ECC-Rater early to avoid missing checks.
- Duct leakage tolerances are tighter. Previously acceptable systems now need more careful sealing by HVAC teams to pass ECC-Rater tests.
FAQ: Your Questions About the ECC Transition
Grizzly HERS Testing
Grizzly HERS Testing is a certified HERS Rater and Energy Consultant. We specialize in Title 24 HERS Verifications, Residential HERS Testing, Mechanical Acceptance Testing and Title 24 Energy Calculations.