Blueprint Newsletter: Summer 2025

2025 Energy Code: Multifamily Summary of Changes

The 2025 Energy Code adds new heat pump water heater (HPWH) and HPWH-ready requirements for multifamily buildings, including ventilation, pipe insulation, and new system options for central water heating systems. Other multifamily updates include increasing envelope efficiency, introducing new requirements for energy recovery ventilation, refining solar photovoltaic (PV) and battery energy storage system (BESS) calculations, clarifying lighting requirements, and increasing the efficiency of pool- and spa-heating equipment.

• Solar PV and Battery Energy Storage Systems
  • Updates PV sizing when using total solar access roof area (SARA): SARA multiplied by 18 for steep-sloped roofs and SARA multiplied by 14 for low-sloped roofs. Section 170.2(f)–(g)
  • Increases minimum PV system size to 4 kWdc for low-rise multifamily for Exception 2 to Section 170.2(f)
  • Updates Exception 5 to apply to high-rise multifamily buildings in areas with no PV compensation through virtual energy bill credits. Section 170.2(g)
  • Updates Table 170.2-U and Table 170.2-V. Sections 170.2(g)–(h):
    • Increases PV capacity factors for some buildings/climate zones. Section 170.2(g)
    • Adds building types in Table 170.2-U and Table 170.2-V: events and exhibits, religious worship, and sports and recreation. Section 170.2(g)-(h)
    • Updates Table 170.2-V BESS capacity factors for all building types and climate zones. Section 170.2(h)
  • Updates Equations 170.2-E, F, and G. Section 170.2(h)
• Envelope
  • Updates mandatory wall insulation maximum U-factors. Section 160.1(b):
    • Metal framed: U-0.151
    • 2x4 Wood framed and others: U-0.095
    • 2x6 Wood framed and others: U-0.069
  • Adds new mandatory requirements for slab edge insulation. Section 160.1(g)
  • Updates prescriptive roofing product efficiencies in Table 170.2-A. Section 170.2(a)1A:
    • Maximum aged solar reflectance (SR) for Option B steep-sloped roofs: aged SR 0.25 in Climate Zones 10, 11, 13, 15; aged SR 0.20 in Climate Zones 12 and 14
    • Option D low-sloped roofs aged SR 0.63 and thermal emittance 0.75, or SRI 75 in Climate Zones 2, 4, 6-15
  • Updates prescriptive fenestration maximum U-factors in Table 170.2-A for all other fenestration. Section 170.2(a)3:
    • U-0.28 in Climate Zones 1,3–5, 11, 13-16
    • U-0.30 in Climate Zones 2, 8–10, 12
    • U-0.34 in Climate Zones 6 and 7
• HVAC
  • Updates requirement that multifamily dwelling units must have a balanced or supply ventilation system, with compartmentalization verified by Energy Code Compliance (ECC)-Rater. Section 160.2(b)2Aivb
  • Adds mandatory requirements for balanced and supply-only ventilation to have accessible air filters, including heat/energy recovery ventilators (HRV/ERVs) for attached dwelling units. Section 160.2(b)2Axi
  • Adds exception for central ventilation system duct sealing requirements for attached dwelling units in low-rise multifamily buildings in Climate Zone 6. Section 160.2(b)2C
  • Updated mandatory requirements for dwelling units. Section 160.3(b):
    • Exception for block loads in determining system size for additions
    • Outdoor design conditions may be selected using Reference Joint Appendix JA2, ASHRAE Handbook Fundamental Volume, or ACCA Manual J
    • Defrost requirements for heat pumps with defrost delay timer
    • Capacity variation requirements for variable or multispeed systems with third-party thermostats
  • Adds mandatory acceptance testing requirements for dedicated outdoor air systems (DOAS) and HRV/ERV systems, with some exceptions. Section 160.3(d)1D
  • Updates prescriptive requirements: balanced systems with HRV/ERV for dwelling units in Climate Zones 1, 2, 4, 11–14, 16; all HRVs and ERVs for dwelling units to have fault indicator display (FID) with ECC-rater verification. Section 170.2(c)3Biv
  • Updates prescriptive requirement for cooling tower to have minimum rated efficiency per Table 170.2-I. Section 170.2(c)4Fv
  • Revises prescriptive requirements for DOAS. Section 170.2(c)4N
  • Adds exception for dwelling unit air leakage test for additions. Section 180.1(a)2
  • Adds exception for dwelling unit air leakage test for alterations, Section 180.2(b)5
• Lighting
  • Updates mandatory requirements for dwelling units: all installed luminaires and light sources to meet JA8 criteria; removes Table 160.5-A and references. Section 160.5(a)1A
  • Clarifies lighting integral to kitchen range hoods and bathroom exhaust fans do not require dimming controls. Section 160.5(a)2F
  • Updates and clarifies mandatory common area lighting requirements:
    • Manual controls to be located such that controlled lighting or status can be seen when operating controls. Section 160.5(b)4A
    • Multilevel controls must provide and enable continuous dimming from 100 to 10 percent or lower; removes Table 160.5-B; Exception 3 allows HID and induction luminaires to have one control step between 30 and 70 percent. Section 160.5(b)4B
    • Occupant-sensing controls must have no more than 20-minute time delay; Exception 4 applies only to emergency lighting intended to function only when normal power is absent. Section 160.5(b)4Ci
    • Lighting in restaurants does not require automatic holiday shut-off feature with automatic time-switch controls. Section 160.5(b)4Civ
    • Occupancy sensing control zones for offices greater than 250 square feet must be shown on plans. Section 160.5(b)4Cvi
    • Daylight responsive controls are now required in daylit zones with 75 watts or more of general lighting; luminaires longer than 8 feet must be controlled in segments up to 8 feet; Exception 3 applies to secondary sidelit daylit zones with less than 85W of general lighting from daylight responsive controls, when primary sidelit daylit zones do not require daylight responsive controls. Section 160.5(b)4D
    • Control interactions for occupied-standby space-conditioning zones. Section 160.5(b)4F
  • Clarifies which outdoor luminaires require motion sensors. Section 160.5(c)2Ci
  • Removes prescriptive Tailored Method of calculating lighting power allowances in common use areas; some allowances moved to Area Category Method. Section 170.2(e)3D and 4B
  • Removes most automatically compliant, sign light sources. Section 170.2(e)7B
• Water Heating
  • Updates requirements for heat pump water heaters (HPWHs):
    • HPWHs with unconditioned inlet air must have backup heat, unless compressor cutoff temperature below local Heating Winter Median of Extremes. Section 110.3(c)7A
    • Adds ventilation or minimum space volume requirements when installing consumer integrated HPWH. Section 110.3(c)7B
  • Adds piping insulation requirements, insulation on first 8 feet of cold water piping, insulation continuity, pipe supports must be on outside of insulation, isolation valves must be extended-stem, and insulation for hot water plumbing appurtenances. Section 160.4(e)
  • Updates prescriptive water heater options for multifamily dwellings with individual water heaters; removes tankless gas water heaters (low-rise multifamily buildings only), adds 120V HPWH. Section 170.2(d)1
  • Updates prescriptive requirements for central systems. Section 170.2(d)2:
    • HPWH can meet NEEA Advanced Water Heater Specification for Commercial HPWH Tier 2 or above
    • Primary HPWH must be single-pass
    • All hot water pipes must meet California Plumbing Code Appendix M
    • Systems serving buildings with more than eight dwellings must have recirculation systems with thermostatic mixing valve on each supply and return loop, meet RA4.4.19
    • Pipe insulation requires ECC-rater verification per RA3.6.3
• Pools and Spas
  • Adds pool and spa heaters must be tested to new standards, by fuel type. Section 110.4(b)
  • The new requirement for primary pool and spa heaters to be heat pump, solar, or use at least 60 percent renewable/recovered energy, sized appropriately. Section 110.4(c)
  • Adds controls for heat pump pool heaters must prevent supplementary heating when load can be met by heat pump alone. Section 110.4(d)
  • Clarifies public pools and spas must meet requirements under Section 150.0(p)2–4. Section 160.7(b)
• Electric Ready
  • Adds mandatory HPWH-ready requirements for individual dwellings and central systems, including dedicated receptacle, condensate drain, designated space, and ventilation. Section 160.9(e-f)
• Performance Approach
  • Updates the energy budget to be expressed in terms of long-term system cost (LSC) and source energy. For multifamily, the source energy budget applies the mandatory and prescriptive requirements of the standard design, except with a consumer gas or propane water heater, to the proposed design. Section 170.1(a):
    • Total LSC is the sum of Efficiency LSC and LSC energy for solar PV, BESS, and demand flexibility
    • Efficiency LSC is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, lighting, and self-utilization credit
    • Source energy budget sums the same end uses as Total LSC, but in source energy
  • Adds verification requirements for thermal balancing valves with variable-speed circulation pump(s). Section 170.1(b)2D

Download the  2025 Energy Code and the 2025 Reference Appendices on the 2025 Energy Code webpage for more information.

Energy Code Compliance Study

The California Energy Commission (CEC) is conducting a study seeking ways to improve implementation of the Energy Code across all communities.​ Effectively implementing the Energy Code is essential to ensuring real-world results from energy policies. The study will:

• Allow local authorities having jurisdiction (AHJs) to evaluate how well the Energy Code works.
• Help identify practical improvements.
• Inform future policy decisions based on what actually happens in-field.
• Provide tools and resources to support inspections and enforcement.
• Provide understanding of code compliance through data analysis.

In addition, AHJs may qualify for federal funding to enhance Energy Code compliance while working with CEC experts.

There are several ways to get involved: 

• Schedule consultations with CEC staff​
• Join a quarterly advisory group​
• Sign up for more information 

Announcements

• 2025 Energy Code Energy Conservation Manual Certified
  • The CEC has certified the 2025 Energy Conservation Manual, which includes the following support items for nonresidential, multifamily, and single-family buildings:
    • Alternative Calculation Method (ACM) Reference Manuals
    • Compliance Manuals
    • Data Registry Requirements Manual
    • Compliance documents
  • Please visit the 2025 Energy Code webpage to view these items and for more information.
• 2025 Energy Code Compliance Software Approved
  • Recently approved versions of the 2025 Energy Code compliance software are available:
    • Single-family buildings
      • CBECC-Res 2025.1.0
    • Nonresidential and multifamily buildings
      • CBECC 2025.1.0
  • Permit applications submitted on or after January 1, 2026, must use approved 2025 Energy Code compliance software and forms. Visit the 2025 Energy Code compliance software web page for all approved software and expiration dates.
• 2025 Battery Energy Storage System Capacities Corrections
  • 2025 Energy Code Table 140.10-B and Table 170.2-V contain battery energy storage system (BESS) capacity factors that do not align with technical recommendations. Corrections will be published as an errata to the 2025 California Building Standards Code and will take effect on January 1, 2026.
  • These updates are summarized in Table 1.
  • Please visit Docket # 24-BSTD-01 for more information.

• Golden State Registry Approved
  • The CEC approved Golden State Registry (GSR) as a home energy rating system (HERS) Provider and data registry for prescriptive single-family HVAC alterations under the 2022 Energy Code.
  • Single-family projects requiring field verification and diagnostic testing by a HERS rater must register all associated compliance forms with an approved data registry per 2022 Energy Code Section 10-103(a). Projects that do not require HERS rating do not need to register their compliance forms.
  • For more information, please visit the Home Energy Rating System Provider webpage and the Energy Code Support Center HERS webpage.
• Assembly Bill 130
  • Governor Gavin Newsom signed Assembly Bill 130, which pauses new updates to the California Building Standards Code, including the Energy Code, that affect residential units until January 1, 2032. The law also limits cities and counties in adopting stricter local building codes on or after October 1, 2025, unless specific conditions are met.
• Energy Code Support Center Updates
  • New: 2025 Energy Code Significant Changes Overview presentation
  • Please visit the Energy Code Support Center web page for fact sheets, FAQs, guides, training courses, videos, and more resources.

Q&As