The 2025 Title 24 Part 6 (Energy) code expands on the new construction baselines, for single-zone heat pumps, introduced in the 2022 code update.<\/p>\n\n\n\n
It encourages electric-ready buildings, for when owners are ready to invest in those technologies.<\/p>\n\n\n\n
It updates photovoltaic and battery energy storage system standards for nonresidential, and high-rise multifamily buildings to achieve cost effective installations as advancements toward California\u2019s Net Zero 2045 goals.<\/p>\n\n\n\n
Implementation Date: <\/strong>January 1, 2026<\/p>\n\n\n\n Notable:<\/strong> Laboratories are no longer an exempted occupancy type in the 2025 T24 Energy Code.<\/em><\/p>\n\n\n\n Notable:<\/strong> Building Energy Efficiency Ratings are now based on Long-Term System Costs, rather than Time Dependent Valuations. As in the 2022 code, Efficiency, Total, and Source compliance scores have to pass, for the project to comply.<\/em><\/p>\n\n\n\n Section and Table numbers are provided to point the reader toward the code section where these changes are found.<\/strong><\/p>\n\n\n\n Please Note:<\/strong> This article is based on the latest, \u201c15 Day\u201d, codebook. Changes are still being made, in advance of the final codebook release. Section, Table numbers, and language may change.<\/em><\/p>\n\n\n\n Vertical fenestration assemblies require a maximum area weighted average U-factor \u2264 0.47 \u00a7120.7(d)<\/strong>. None of the Default U-factors found in Table 110.6-A<\/strong> meet this new requirement.<\/p>\n\n\n\n If more than 150 sf of vertical fenestration is replaced, it must have a U-factor \u2264 0.58, or the climate zone prescriptive maximum.<\/p>\n\n\n\n In selected occupancies, vestibules are now required for newly constructed buildings (where the doors open directly into a greater than 3,000 sf space) \u00a7120.7(e)<\/strong>.The vestibule must be large enough, so that interior, and exterior doors will not be opened at the same time. Additionally, the doors require self-closing hardware. An air curtain is an acceptable alternative to providing a vestibule. Thermostatic controls are required in conditioned vestibules, for both HVAC, and Heated Air Curtains.<\/p>\n\n\n\n Numerous changes are made to the prescriptive envelope criteria in Table 140.3-B<\/strong>. Maximum U-factors for many types of building assemblies (in most climate zones) are reduced.<\/p>\n\n\n\n There are efficiency changes in Tables 110.2-H, I, & J<\/strong>. These changes affect DOAS, Heat Pump, and Heat Recovery Chiller Packages, in heating, and cooling operations.<\/p>\n\n\n\n The VRF Efficiencies in Table 110.2-F, and Table 110.2-G<\/strong> are adjusted to meet new EER, and SEER2 values \u00a7110.2.<\/strong><\/p>\n\n\n\n The 2025 T24 code introduces a new formula for the calculation of minimum ventilation rates. <\/p>\n\n\n\n Equation 120.1-F<\/strong> uses the larger two equations, one Occupant-based, and another Area-based (Table 120.1-A<\/strong>) \u00a7120.1(c)3.<\/strong><\/p>\n\n\n\n A new exhaust category, for Occupancy L (supporting laboratories, specifically animal containment spaces), appears on Table 120.1-B. \u00a7120.1<\/strong><\/p>\n\n\n\n Title 24 now utilizes the ASHRAE Guideline 36. It covers: Variable Air Volume (VAV) Systems, Economizers, Supply Air Temperature Reset Controls, and DDC Controller Logic. \u00a7140.4<\/strong>. These requirements apply to new or replacement systems, not repairs or upgrades to existing equipment.<\/p>\n\n\n\n (\u2264 150,000 sf, or \u2264 4 Stories), in selected climate zones, must contain one of the following options:<\/p>\n\n\n\n Variable Refrigerant Flow (VRF) Heat Pump with DOAS and refrigerant loop heat recovery \u00a7140.4(a)i.<\/strong><\/p>\n\n\n\n or<\/strong> 4-Pipe Fan Coil (FPFC) Terminal Unit \u2013 Utilizing an Air-to-water Heat Pump (AWHP) with DOAS \u00a7140.4(a) ii.<\/strong><\/p>\n\n\n\n or<\/strong> Variable Air Volume (VAV) \u2013 Utilizing AWHP with DOAS) \u00a7140.4(c) 2.<\/strong><\/p>\n\n\n\n or<\/strong> Dual-Fan Dual-Duct (DFDD)<\/p>\n\n\n\n or<\/strong> Other System (Determined by the Executive Director of the CEC) \u00a7140.4(a)3G.<\/strong><\/p>\n\n\n\n The mandatory requirements for Cooling Tower Fan Efficiency \u00a7140.4(h)5<\/strong> have changed. Additionally, mandatory requirements for cycles of concentration have been revised \u00a7110.2(e.) <\/strong>A new Table 140.4-H-2<\/strong> is added to define Prescriptive Minimum Fan Efficiencies for Open-circuit Cooling Towers \u2265 900gpm.<\/p>\n\n\n\n Simultaneous mechanical heat recovery is required for new buildings that meet one of the two below \u00a7140.4(s)<\/strong>: A Peak Cooling Load of \u2265 200 tons (with a design equipment power density of > 5w sf and minimum OA of <0.5 cfm sf) and service water heating plus space heating \u2265 2,200 kBtuh.<\/p>\n\n\n\n or<\/strong> Cooling Design Capacity \u2265 300 tons and service water heating \u2265 700kBtuh.<\/p>\n\n\n\n < 65,000Btuh HVAC Alterations<\/strong> \u00a7141.0(b) 2Cii.<\/strong> <\/p>\n\n\n\n New or replacement single zone packaged RTUs with DX cooling and a capacity < 65,000Btuh are required to comply with Table 141.0-E-1<\/strong> or the performance requirements of \u00a7141.0(b)3<\/strong>.<\/p>\n\n\n\n Laboratory Exhaust Systems<\/strong> \u00a7140.9(c)<\/strong> are now subject to the prescriptive requirements of the Energy Code. <\/p>\n\n\n\n Notable:<\/em><\/strong> Healthcare facilities are exempted.<\/em><\/p>\n\n\n\n The 2025 code expands the mandatory pipe insulation requirements to cover process heating and cooling systems. Insulation values are defined in Table 120.3-A-1 and Table 120.3-A-2. Additionally, there is a new equation in \u00a7120.3(c)<\/strong> to calculate the minimum insulation thickness for \u201cinsulation with a conductivity outside the range\u201d given in the two tables.<\/p>\n\n\n\n These create new mandatory requirements for Electric Ready Quick-service and Institutional Commercial Kitchens. Branch circuit conductors rated at \u2265 50 amps and an electrical service panel capacity \u2265 800 connected amps are required.<\/p>\n\n\n\n In addition, the electrical service panel must be sized to accommodate an additional 208v or 240V 50 amp breaker.<\/p>\n\n\n\n Notable:<\/em><\/strong> Healthcare facilities and all-electric commercial kitchens are exempted from this new provision.<\/em><\/p>\n\n\n\n Manual area control requirements are simplified. \u00a7130.1(a)<\/strong><\/p>\n\n\n\n Daylighting Controls \u00a7130.1(d)<\/strong> for primary and secondary zones have reduced triggers of 75w, and controlled segments are now restricted to 8 feet or less\u00a7130.1(d)Biii<\/strong>.<\/p>\n\n\n\n There have been numerous changes to the Complete Building Method \u00a7140.6(c)1 (Table 140.6-B)<\/strong> and the Area Category Method \u00a7140.6(c)2 (Table 140.6-C)<\/strong>.<\/p>\n\n\n\n Additional allowances have changed in the space types indicated on Table 140.6-C<\/strong>:<\/p>\n\n\n\n Notable: <\/em><\/strong>see below for changes to the Tailored Method.<\/em><\/p>\n\n\n\n The Tailored Method of lighting compliance is removed from the 2025 Title 24 code. <\/p>\n\n\n\n There is a new exception for luminaire shielding requirements, changes to automatic scheduling controls, and changes in the requirements for motion sensing controls.<\/p>\n\n\n\n Signs now have only two approved sources for illumination: LED and Neon. HPS, MH, Fluorescent, and CFL are no longer allowed.<\/p>\n\n\n\n There have been several modifications to the Solar Photovoltaic and Battery Storage requirements for new nonresidential buildings. In mixed occupancy buildings, where at least 80% of the floor area of the building serves one of the required occupancies, a PV system must be installed to meet the requirements of \u00a7140.10(a).<\/p>\n\n\n\n Solar PV requirements (expressed in KW DC) are met by the smaller of two options:<\/p>\n\n\n\n Sizing the PV system by Equation 140.10-A<\/strong>. The equation is unchanged, although the PV Capacity Factors on Table 140.10-A<\/strong> have new occupancies, and many capacity factors have changed. <\/p>\n\n\n\n Notable: <\/em><\/strong>Restaurant occupancies have seen the greatest increase in PV capacity factor. Additionally, there are new requirements for Event & Exhibits, Religious Worship, and Sports & Recreation.<\/em><\/p>\n\n\n\n The formula inputs for using the Solar Access Roof Area (SARA) <\/strong>calculation have changed. There are now two W\/sf values depending on the type of roof \u2013 14W\/sf for Low-Slope Roofs and 18W\/sf for Steep-Slope Roofs. A project with both roof types would sum the two different roof types to get the total capacity needed. See \u00a7140.10(a)<\/strong> for added exceptions to the Solar Photovoltaic and Battery Storage requirements.<\/p>\n\n\n\n New buildings required to have a Photovoltaic System by \u00a7140.10(a)<\/strong> must have a Battery Energy Storage System \u00a7140.10(b)<\/strong>. The minimum rated useable energy capacity of the Battery Energy Storage System is determined by Equation 140.10-B<\/strong>, if Equation 140.10-A<\/strong> was used to determine the system capacity, or Equation 140.10-C<\/strong> if the SARA method was used. For either method, Equation 140.10-D<\/strong> is used to determine the minimum power capacity. In mixed occupancy buildings, the total battery capacity is found by summing the minimum rated usable energy capacity for each required occupancy. As with PV Systems, BESS Capacity Factors have been updated.<\/p>\n\n\n\n As with every revision, the 2025 edition of the Title 24, Part 6 code moves us another step down the road to a cleaner, greener future. As usual, these changes will move California ahead in the race toward Net Zero\/Greenhouse Gas Reduction. But the lag between it and the rest of the country is narrowing. With advances in the IECC\/ASHRAE codes, the rollout of LEED v5, improvements in the International Green Construction Code, and greenhouse gas reduction laws like NYC\u2019s Local Law 97, the movement toward a carbon neutral future is coming closer.<\/p>\n\n\n\n Have questions about the 2025 Title 24 updates? Contact Schnackel Engineers<\/a> today and let our experts help keep your project compliant and on schedule.<\/p>\n","protected":false},"excerpt":{"rendered":"ENVELOPE<\/strong><\/h2>\n\n\n\n
Fenestration<\/h3>\n\n\n\n
Vestibules<\/h3>\n\n\n\n
Building Assemblies<\/h3>\n\n\n\n
Mechanical<\/strong><\/h2>\n\n\n\n
Changes in HVAC Efficiencies<\/h3>\n\n\n\n
Ventilation and Exhaust<\/h3>\n\n\n\n
ASHRAE Guideline 36 (\u201cHigh-Performance Sequences of Operation for HVAC Systems\u201d)<\/h3>\n\n\n\n
Offices and Schools with Multi-zone Systems (varies by climate zone) \u00a7140.4(a)3<\/h3>\n\n\n\n
Cooling Towers<\/h3>\n\n\n\n
Heat Recovery<\/h3>\n\n\n\n
Pipe Insulation for Covered Processes \u00a7120.3(a)<\/h3>\n\n\n\n
Electrical<\/strong><\/h2>\n\n\n\n
Electric Ready Commercial Kitchens \u00a7120.6(k)<\/h3>\n\n\n\n
Indoor Lighting Controls \u00a7130.1<\/h3>\n\n\n\n
Prescriptive Requirements for Indoor Lighting
\u00a7140.6(b & c)<\/h3>\n\n\n\n\n
Tailored Method removed from Allowed Indoor Lighting Power Calculation<\/h3>\n\n\n\n
Outdoor Lighting Controls and Equipment \u00a7130.2<\/h3>\n\n\n\n
Sign Lighting \u00a7140.8<\/h3>\n\n\n\n
Solar Photovoltaic and Battery Storage \u00a7140.10<\/strong><\/h2>\n\n\n\n
Battery Energy Storage System (BESS)<\/h3>\n\n\n\n
Conclusion<\/strong><\/h2>\n\n\n\n