CALGreen · California Green Building Standards Code (CALGreen)
Energy performance requirements and prescriptive/performance paths for low‑rise residential
If your new house uses the CALGreen performance route, you must use Energy Commission‑certified software to meet a tougher Long‑Term System Cost target (the climate‑zone margin in Table A4.203.1.1) and also implement at least two specified efficiency measures from § A4.203.1.2; include the computed rating on the Certificate of Compliance (see § A4.203.1.1 and § A4.203.1.2) .
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
Newly constructed low‑rise residential buildings choosing the CALGreen performance route must meet an enhanced energy‑cost (LSC) target computed by Energy Commission‑certified compliance software and also satisfy at least two specified efficiency prerequisites. The enhanced Long‑Term System Cost target is set by the compliance margin in Table A4.203.1.1 and is required by § A4.203.1.1; the prerequisite options are listed in § A4.203.1.2. These provisions sit inside the CALGreen voluntary residential measures for exemplary energy efficiency and are triggered when a jurisdiction adopts Appendix A4 measures (see § A4.203.1) (see ).
Designers must use Energy Commission‑certified compliance software to meet a stricter Long‑Term System Cost (LSC) target (the Table A4.203.1.1 margin) and must also comply with at least two efficiency prerequisites listed in § A4.203.1.2 (see § A4.203.1.1 and § A4.203.1.2, respectively) (see ).
Requirements in detail
Key defined terms (first mention bolded)
- Long‑Term System Cost (LSC) — the LSC energy budget computed by certified compliance software (used as the compliance metric for the performance path) (see § A4.203.1.1) (see ).
- Proposed Design — the actual building design being modeled by the compliance software to demonstrate compliance (see § A4.203.1.1) (see ).
- Compliance Software — Commission‑certified energy compliance software required to compute the LSC and energy budgets (see § A4.203.1.1) (see ).
What the performance rule actually requires
- Use Commission‑certified compliance software to compute the building LSC for the Proposed Design (see § A4.203.1.1) (see ).
- Reduce the software’s minimum LSC requirement by the Total LSC compliance margin given for the project’s climate zone in Table A4.203.1.1; the reduced (more stringent) LSC is the target the Proposed Design must meet (see § A4.203.1.1 and Table A4.203.1.1) (see ).
- In addition to meeting the LSC margin, the project must satisfy a minimum of two mandatory prerequisite options from § A4.203.1.2 (see § A4.203.1.2) (see ).
- The rating (LSC result) must be included in the Certificate of Compliance documentation (see § A4.203.1.1) (see ).
Decision‑relevant numeric table (Code Reference)
| Decision dimension | Value / options | Code reference |
|---|---|---|
| Compliance metric | Long‑Term System Cost (LSC) (computed by certified software) | § A4.203.1.1 |
| Must‑meet LSC adjustment | Climate‑zone dependent Total LSC compliance margins (see table below) | § A4.203.1.1; Table A4.203.1.1 |
| Number of required prerequisites | Minimum of two measures chosen from § A4.203.1.2.1–.2.8 | § A4.203.1.2 |
| Prerequisite examples | Roof deck insulation / ducts in conditioned space; High‑performance walls; Compact hot water distribution; Drain‑water heat recovery; High‑performance vertical fenestration; HPWH demand management; BESS controls; Heat‑pump space & water heating | § A4.203.1.2 (list) |
| Documentation | Include the computed LSC rating and Certificate of Compliance | § A4.203.1.1 |
Detailed climate‑zone margins (from Table A4.203.1.1)
| Climate zone | Total LSC compliance margin |
|---|---|
| 1 | 2.70 |
| 2 | 1.62 |
| 3 | 1.10 |
| 4 | 1.11 |
| 5 | 1.01 |
| 6 | 0.24 |
| 7 | 0.24 |
| 8 | 0.21 |
| 9 | 0.20 |
| 10 | 0.18 |
| 11 | 1.11 |
| 12 | 1.05 |
| 13 | 0.96 |
| 14 | 1.21 |
| 15 | 0.59 |
| 16 | 1.68 |
| (Values from Table A4.203.1.1; see § A4.203.1.1) |
The prerequisite options (summary)
At least two of the following must be provided (see § A4.203.1.2):
- Roof deck insulation or ducts in conditioned space (options include R‑19 below deck, continuous R‑8 above deck with air space, or all ducts/air handlers in conditioned space per Reference Appendix RA3.1) — § A4.203.1.2.1 .
- High‑performance walls (meet the climate‑zone U‑factor or R‑value specified in T24 § 150.1(c)1B; max U = 0.048) — § A4.203.1.2.2 .
- Compact hot water distribution system (as specified in Reference Appendix RA3.6.5) — § A4.203.1.2.3 .
- Drain water heat recovery — § A4.203.1.2 (see list) .
- High performance vertical fenestration — § A4.203.1.2 (see list) .
- Heat pump water heater demand management — § A4.203.1.2 (see list) .
- Battery energy storage system (BESS) controls — § A4.203.1.2 (see list) .
- Heat pump space and water heating — § A4.203.1.2 (see list) .
(Complete requirement text and specific installation/verification details for each option are stated in the subsections of § A4.203.1.2) .
Exceptions & special cases
- Community‑shared renewable or storage solutions that meet Title 24, Part 1, § 10‑115 may be used to help achieve the LSC targets in Table A4.203.1.1 (see Note in Table A4.203.1.1 and § A4.203.1.1) .
- Local jurisdictions considering reduced EDR/EDR‑type targets that rely on larger PV systems should consult the local electric service provider to ensure proposed PV sizing is acceptable (see § A4.203.1.3) .
- These Appendix A4 provisions are voluntary unless a local jurisdiction adopts them as mandatory; jurisdictional adoption requires Energy Commission filing/approval per § A4.201.1 (see § A4.203.1 and § A4.201.1) .
If a specific procedural or unit conversion question is required (for example, how the numeric margin in Table A4.203.1.1 maps to the software output units), that detail is specified by the Energy Commission‑certified compliance software and related Reference Manuals rather than in the brief Table header; consult the software guidance and the Residential ACM/Reference Manual for exact computation steps (see § A4.203.1.1) .
Common mistakes
- Assuming the Table margin is in kWh or dollars without checking the compliance software’s LSC units — the LSC is the software’s computed metric; use the certified tool outputs (see § A4.203.1.1) .
- Meeting the LSC margin but failing to select and document two prerequisite measures from § A4.203.1.2 — both requirements are mandatory for this CALGreen performance route (see § A4.203.1.2) .
- Forgetting to include the computed LSC rating on the Certificate of Compliance (the rating must be included per § A4.203.1.1) .
- Using non‑certified software or an uncertified compliance method to generate the LSC — the code requires Energy Commission‑certified compliance software (see § A4.203.1.1) .
- Overlooking local adoption/effective dates: Appendix A4 provisions are only mandatory in a jurisdiction after that jurisdiction files and receives required approvals (see § A4.201.1) .
Worked example — single‑family house in Climate Zone 3
Scenario: New detached single‑family home in Climate Zone 3 chooses the CALGreen performance route.
Step 1 — Determine the LSC margin:
- From Table A4.203.1.1, Climate Zone 3 has a Total LSC compliance margin = 1.10 (see § A4.203.1.1) .
Step 2 — Run the certified compliance software:
- Use Energy Commission‑certified compliance software to compute the standard design minimum LSC and the Proposed Design LSC (software provides both). The CALGreen requirement is to apply the 1.10 margin to the software’s minimum performance LSC so that the software’s required LSC becomes the more stringent target identified by subtracting/applying the margin as required by the software’s methodology (see § A4.203.1.1) .
- Note: The exact way the margin is applied (additive or software‑specific adjustment) follows the compliance software’s defined procedure and reporting; consult the software guidance and the Certificate of Compliance output for the applied adjustment (see § A4.203.1.1) .
Step 3 — Select prerequisites:
- Choose two prerequisite options from § A4.203.1.2. Example choices:
- High‑performance walls (meet U‑factor/R‑value per T24) and
- Compact hot water distribution system (per Reference Appendix RA3.6.5) — both are listed in § A4.203.1.2 (see ).
Step 4 — Document and submit:
- Include the computed LSC rating and the Certificate of Compliance showing the applied margin and that the Proposed Design meets the reduced LSC target. Also document the two prerequisites and any field verification items required by the software or reference manuals (see § A4.203.1.1 and § A4.203.1.2) .
(If you need a step‑by‑step run‑through using a specific certified compliance tool, provide the tool name and I can map the CALGreen steps to that tool’s input/output fields. The code text delegates the numeric LSC computation and exact adjustment method to the certified software documentation — see § A4.203.1.1) .
Related provisions
- § A4.203.1 — Performance approach for newly constructed low‑rise residential buildings (overview) .
- § A4.203.1.1 — Long‑Term System Cost requirement and Table A4.203.1.1 (LSC margins) .
- § A4.203.1.2 — Prerequisite options (must meet at least two) .
- § A4.203.1.3 — Consultation with local electric service provider if relying on larger PV systems / reduced EDR targets .
- § A4.201.1 — Scope and adoption requirements for Appendix A voluntary provisions (jurisdictional adoption and filing) .
- Title 24, Part 6 (California Energy Code) — referenced for prescriptive U‑factor/R‑values, Reference Appendices and certified compliance software requirements; CALGreen performance route relies on these T24 references (see § A4.203.1.1 and § A4.203.1.2) .
Code references
Grounded in the retrieved California Green Building Standards Code (CALGreen) — click a citation to read the verbatim passage:
CALGreen § 3.1. High relevance — show source text
- From Division A4.3, Water Efficiency and Conservation. 3.1. Comply with at least two elective measures selected from Division A4.3.
- From Division A4.4, Material Conservation and Resource Efficiency. 4.1. Comply with the 20 percent cement reduction requirements in Section A4.403.2. 4.2. Comply with the 10 percent recycled content requirements in Section A4.405.3.1. 4.3. Comply with the 65 percent reduction in construction waste in Section A4.408.1. 4.4. Comply with at least two elective measures selected from Division A4.4.
- From Division A4.5, Environmental Quality. 5.1. Comply with the 90 percent resilient flooring systems requirements in Section A4.504.2. 5.2. Comply with the thermal insulation requirements for Tier 1 in Section A4.504.3. 5.3. Comply with at least one elective measure selected from Division A4.5.
Note: The Residential Occupancies Application Checklist contained in Section A4.602 may be used to show which elective measures are selected.
A4.601.5 Tier 2. To achieve Tier 2 status a project must comply with the following.
Note: The measures necessary to achieve Tier 2 status are very stringent. Cities, counties, and cities and counties considering adoption of Tier 2 as mandatory should carefully consider the stringency of each measure and ensure that the measures are achievable in their location.
A4.601.5.1 Mandatory measures for Tier 2. The project shall meet or exceed all of the mandatory measures in Chapter 4, Divisions 4.1 through 4.5 and Chapter 7 as applicable.
A4.601.5.2 Prerequisite and elective measures for Tier 2. In addition to the mandatory measures, compliance with the following prerequisite and elective measures from Appendix A4 is also required to achieve Tier 2 status.
- From Division A4.1, Planning and Design.
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APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES
1.1. Comply with the topsoil protection requirements for Tier 1 and Tier 2 in Section A4.106.2.3. 1.2. Comply with the 30 percent permeable paving requirements in Section A4.106.4. 1.3. Comply with the cool roof requirements in Section A4.106.5. 1.4. Comply with the Tier 2 electric vehicle (EV) charging requirements in Section A4.106.8. 1.5. Comply with at least four elective measures selected from Division A4.1. 2. From Division A4.2, Energy Efficiency. 2.1. For newly constructed low-rise residential buildings, comply with the energy efficiency requirements in Sections A4.203.1, A4.203.1.1, Table A4.203.1.1, A4.203.1.2 and A4.203.1.3.
- From Division A4.3, Water Efficiency and Conservation. 3.1. Comply with at least three elective measures selected from Division A4.3.
- From Division A4.4, Material Conservation and Resource Efficiency. 4.1.
CALGreen § 10-103 High relevance — show source text
- Compliance demonstration requirements for performance standards. A. Certificate of compliance and application for a building permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 which demonstrates, using an approved calculation method, that the building has been designed so that its energy consumption does not exceed the standard design energy budgets for the applicable climate zone. Exception to Section 150.1(b)2A Multiple orientation: A permit applicant may demonstrate compliance with the energy budget requirements of Section 150.1(a) and (b) for any orientation of the same building model if the documentation demonstrates that the building model with its proposed designs and features would comply in each of the four cardinal orientations.
B. Field verification. When performance of installed features, materials, components, manufactured devices or systems above the minimum specified in Section 150.1(c) is necessary for the building to comply with Section 150.1(b), or is necessary to achieve a more stringent local ordinance, field verification shall be performed in accordance with the applicable requirements in the following subsections, and the results of the verification(s) shall be documented on applicable certificates of installation pursuant to Section 10-103(a)3 and applicable certificates of verification pursuant to Section 10-103(a)5. i. EER2/SEER2/CEER/HSPF2 Rating. When performance compliance requires installation of a space-conditioning system with a rating that is greater than the minimum rating required by Table 150.1-A or specified for the standard design, the installed system shall be field verified in accordance with the procedures specified in the applicable sections of Reference Residential Appendix RA3.4. ii. Variable capacity heat pump (VCHP) compliance option. When performance compliance requires installation of a heat pump system that meets all the requirements of the VCHP compliance option specified in the ACM
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SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
Reference Manual, the system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.4.4.3. iii. Low leakage air handler. When performance compliance requires installation of a low leakage air-handling unit, the installed air-handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9.
iv. Reserved.
v. Heat pump — rated heating capacity. When performance compliance requires installation of a heat pump system, the heating capacity values at 47°F and 17°F shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.4. vi. Whole-house fan. When performance compliance requires installation of a whole-house fan, the whole-house fan ventilation airflow rate and fan efficacy shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.9. vii. Central fan ventilation cooling system. When performance compliance requires installation of a central fan ventilation cooling system, the installed system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.3.4. viii. Building enclosure air leakage. When performance compliance requires a building enclosure leakage rate that is lower than the standard design, the building enclosure shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.8. ix. **Quality Insulation Installation (QII).
CALGreen § 601.5.2 High relevance — show source text
A4.601.5.2 Prerequisite and elective measures for Tier 2. In addition to the mandatory measures, compliance with the following prerequisite and elective measures from Appendix A4 is also required to achieve Tier 2 status.
- From Division A4.1, Planning and Design.
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APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES
1.1. Comply with the topsoil protection requirements for Tier 1 and Tier 2 in Section A4.106.2.3. 1.2. Comply with the 30 percent permeable paving requirements in Section A4.106.4. 1.3. Comply with the cool roof requirements in Section A4.106.5. 1.4. Comply with the Tier 2 electric vehicle (EV) charging requirements in Section A4.106.8. 1.5. Comply with at least four elective measures selected from Division A4.1. 2. From Division A4.2, Energy Efficiency. 2.1. For newly constructed low-rise residential buildings, comply with the energy efficiency requirements in Sections A4.203.1, A4.203.1.1, Table A4.203.1.1, A4.203.1.2 and A4.203.1.3.
- From Division A4.3, Water Efficiency and Conservation. 3.1. Comply with at least three elective measures selected from Division A4.3.
- From Division A4.4, Material Conservation and Resource Efficiency. 4.1. Comply with the 25 percent cement reduction requirements in Section A4.403.2. 4.2. Comply with the 15 percent recycled content requirements in Section A4.405.3.1. 4.3. Comply with the 75 percent reduction in construction waste in Section A4.408.1. 4.4. Comply with at least four elective measures selected from Division A4.4.
- From Division A4.5, Environmental Quality. 5.1. Comply with the 100 percent resilient flooring systems requirements in Section A4.504.2. 5.2. Comply with the thermal insulation requirements for Tier 1 and Tier 2 in Section A4.504.3. 5.3. Comply with at least one elective measure selected from Division A4.5.
Note: The Residential Occupancies Application Checklist contained in Section A4.602 may be used to show which elective measures are selected.
APPENDIX A4-22 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE
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DIVISION A4.6 – TIER 1 AND TIER 2
SECTION A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST
CALGreen § 150.1 High relevance — show source text
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8 SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE
AND PRESCRIPTIVE COMPLIANCE APPROACHES
SECTION 150.1—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR SINGLE-FAMILY RESIDENTIAL BUILDINGS
(a) Basic requirements. Single-family residential buildings shall meet all of the following:
- The applicable requirements of Sections 110.0 through 110.10.
- The applicable requirements of Section 150.0 (mandatory features).
- Either the performance standards or the prescriptive standards set forth in this section for the climate zone in which the building is located. Climate zones are shown in Reference Joint Appendix JA2–Weather/Climate Data. Exception to Section 150.1(a)3: If a single contiguous subdivision or tract falls in more than one climate zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the climate zone that contains 50 percent or more of the dwelling units. Note: The Commission periodically updates, publishes, and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, as specified in Reference Joint Appendix JA2–Weather/Climate Data.
Note: The requirements of Sections 150.0(a) through 150.0(r) apply to newly constructed buildings and Sections 150.2(a) and 150.2(b) specifies changes to the requirements of Sections 150.1(a) through 150.1(c) that apply to additions or alterations.
(b) Performance approach. A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.
- Energy budget. The energy budget is expressed in terms of source energy and long-term system cost (LSC). A. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.
i. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, and the self-utilization credit.
ii. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), lighting, demand flexibility, and other plug loads. B. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building. The source energy is the total annual source energy. Exception to Section 150.1(b)1. A community shared solar electric generation system, or other renewable electric generation system, or community shared BESS, which provides dedicated power, utility energy reduction credits, or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system and demand flexibility Energy Design Rating required to comply with the Standards, as calculated according to methods established by the Commission in the Residential ACM Reference Manual.
CALGreen § 108.1 High relevance — show source text
108.1** Items in this section are necessary to address innovative
concepts or local environmental conditions.||||||| |Item 1|
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| |Item 3||||||| |ENERGY EFFICIENCY||||||| |General||||||| |4.201.1 Building meets or exceeds the requirements of the_California_
_Building Energy Efficiency Standards_3.||2|2|||| |Performance Approach for Newly
Constructed Buildings||||||| |**A4.203.1.1 Hourly Source Energy Rating (EDR1).**EDR1 ratings for
building design shall be computed by Energy Compliant software and
shall reduce the EDR1 required by the software by the compliance
margins specified in Table A4.203.1.1.||2|2|||| |**A4.203.1.2 Prerequisite options.In addition, a minimum of two of
the efficiency measures specified in Sections A4.203.1.2.1 through
A4.203.1.2.8 will be required to be met.
· Roof Deck Insulation or Ducts in Conditioned Space.
· High-performance Walls.
· Compact Hot Water Distribution System.
· Drain Water Heat Recovery.
· High Performance Vertical Fenestration.
· Heat Pump Water Heater Demand Management.
· Battery Storage System Controls.
· **Heat Pump Space and Water Heating.||2|2|||| |**A4.203.1.3 Consultation with local electric service provider.**Local
jurisdictions considering adoption of reduced EDR targets based on
using solar photovoltaic (PV) systems larger than required by the
California Energy Code shall consult with the local electric service
provider to ensure that that PV system sizing required to comply with
the EDR targets will be acceptable to the local electric service
provider.||2|2||||2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A4-25
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APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES
SECTION A4.602—RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST—continued
CALGreen § 170.1 High relevance — show source text
A. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, lighting and the self-utilization credit. B. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), and demand flexibility. 2. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design, except with a consumer gas or propane water heater, to the proposed design building.
Exception to Section 170.1(a): A community shared solar electric generation system, or other renewable electric generation system, and/or community shared BESS, that provides dedicated power, utility energy reduction credits or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system or BESS LSC energy required to comply with the standards, as calculated according to methods established by the Commission in the Nonresidential ACM Reference Manual.
(b) Compliance demonstration requirements for performance standards.
- Certificate of Compliance and Application for a Building Permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 that demonstrates, using an approved calculation method, that the building has been designed so that its source energy and LSC energy consumption do not exceed the standard design energy budgets for the applicable climate zone.
- Field verification of individual dwelling unit systems. When performance of installed features, materials, components, manufactured devices or systems above the minimum specified in Section 170.2 is necessary for the building to comply with Section 170.1, or is necessary to achieve a more stringent local ordinance, field verification shall be performed in accordance with the applicable requirements in the following subsections, and the results of the verification(s) shall be documented on applicable Certificates of Installation pursuant to Section 10-103(a)3 and applicable Certificates of Verification pursuant to Section 10-103(a)5. A. EER2/SEER2/CEER/HSPF2 Rating. When performance compliance requires installation of a space-conditioning system with a rating that is greater than the minimum rating required by Table 170.2-K or specified for the standard
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MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
design, the installed system shall be field verified in accordance with the procedures specified in the applicable sections of Reference Residential Appendix RA3. B. Variable capacity heat pump (VCHP) compliance option. When performance compliance requires installation of a heat pump system that meets all the requirements of the VCHP compliance option specified in the ACM Reference Manual, the system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.4.4.3.
C. Low leakage air handler. When performance compliance requires installation of a low leakage air-handling unit, the installed air handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9. D. Thermal balancing valve. When performance compliance requires installation of thermal balancing valves with variable speed circulation pump(s), the installation shall meet the procedures specified in Reference Residential Appendix RA4.4.3. E. Heat pump—rated heating capacity.
CALGreen § 201.1 High relevance — show source text
SECTION A4.201—GENERAL
A4.201.1 Scope. For the purposes of mandatory energy efficiency standards in the California Building Standards Code (Title 24), the California Energy Commission will continue to adopt mandatory standards in the California Energy Code (Title 24, Part 6). It is the intent of these voluntary provisions to encourage local jurisdictions through codification to achieve exemplary performance in the area of building energy efficiency. Local jurisdictions adopting these voluntary provisions as mandatory local energy efficiency standards shall submit the required application and receive the required approval of the California Energy Commission in compliance with Title 24, Part 1, Section 10-106 prior to enforcement. Once the required filing has been verified and finding has been made by the Energy Commission, local jurisdictions shall file an ordinance expressly marking the local modification along with findings and receive the required acceptance from the California Building Standards Commission in compliance with Section 101.7 of this code, prior to enforcement. (Title 24, Part 1, Section 10-106 is available at https://www.energy.ca.gov/programs-and-topics/programs/build- ing-energy-efficiency-standards/2025-building-energy-efficiency
SECTION A4.202—DEFINITIONS
A4.202.1 Definitions. The following terms are defined in Chapter 2.
ENERGY BUDGET.
LONG-TERM SYSTEM COST (LSC).
RECOVERED ENERGY, ON-SITE.
SOLAR POOL HEATING SYSTEM.
SECTION A4.203—PERFORMANCE APPROACH FOR NEWLY CONSTRUCTED BUILDINGS
A4.203.1 Energy efficiency. Newly constructed low-rise residential buildings shall comply with Sections A4.203.1.1 through A4.203.1.4.
A4.203.1.1 Long-term system cost (LSC). LSC rating for the building’s Proposed Design shall be computed by Compliance Software certified by the Energy Commission as specified in Title 24, Part 6, Section 100.1 and 150.1(b), and shall reduce the LSC required in the Compliance Software for minimum performance-based compliance with the California Energy Code by the compliance margin specified in Table A4.203.1.1. The rating shall be included in the Certificate of Compliance documentation.
TABLE A4.203.1.1—RECOMMENDED LSC MARGINS BY CLIMATE ZONES Col2 CALIFORNIA ENERGY CODE CLIMATE ZONE TOTAL LSC COMPLIANCE MARGIN 1 2.70 2 1.62 3 1.10 4 1.11 5 1.01 6 0.24 7 0.24 8 0.21 9 0.20 10 0.18 11 1.11 12 1.05 13 0.96 14 1.21 15 0.59 16 1.68 Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets. Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets. 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A4-9
CALGreen § 4.4.3. High relevance — show source text
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SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
Reference Manual, the system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.4.4.3. iii. Low leakage air handler. When performance compliance requires installation of a low leakage air-handling unit, the installed air-handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9.
iv. Reserved.
v. Heat pump — rated heating capacity. When performance compliance requires installation of a heat pump system, the heating capacity values at 47°F and 17°F shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.4. vi. Whole-house fan. When performance compliance requires installation of a whole-house fan, the whole-house fan ventilation airflow rate and fan efficacy shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.9. vii. Central fan ventilation cooling system. When performance compliance requires installation of a central fan ventilation cooling system, the installed system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.3.4. viii. Building enclosure air leakage. When performance compliance requires a building enclosure leakage rate that is lower than the standard design, the building enclosure shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.8. ix. Quality Insulation Installation (QII). When performance compliance requires field verification of QII, the building insulation system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.5.
(c) Prescriptive standards/component packages. Buildings that comply with the prescriptive standards shall be designed, constructed and equipped to meet all of the requirements for the appropriate climate zone shown in Table 150.1-A. In Table 150.1-A, an NA (not allowed) means that feature is not permitted in a particular climate zone and an NR (no requirement) means that there is no prescriptive requirement for that feature in a particular climate zone. Installed components shall meet the following requirements:
- Insulation.
A. Roof and ceiling insulation shall be installed with an R -value equal to or greater than that shown in Table 150.1-A meeting Option i, ii or iii below. i. Option A: Reserved. ii. Option B: A minimum R -value of insulation in a ventilated attic installed between the roof rafters in contact with the roof deck and an additional layer of ceiling insulation located between the attic and the conditioned space when meeting Section 150.1(c)9A; or iii. Option C: A minimum R -value of ceiling insulation located between a ventilated attic and the conditioned space or within a cathedral ceiling assembly shall comply with Section 150.1(c)9B.
B. Walls.
CALGreen § 203.2 High relevance — show source text
SECTION A6.203—PERFORMANCE APPROACH
A6.203.2 Energy performance. It is the intent of this code to encourage green buildings to achieve exemplary performance in the area of energy efficiency.
A6.203.2.1 CALGreen Tier 1. [OSHPD 1] To achieve CALGreen [Tier 1, buildings must comply with the latest edition of “Savings By](http://www.energysoft.com/ep/ 2007SBDHProcedures.pdf) Design, Healthcare Modeling Procedures” found online at http://www.energysoft.com/ep/ 2007SBDHProcedures.pdf.
A6.203.2.2 CALGreen Tier 2. [OSHPD 1] To achieve CALGreen Tier 2, buildings must exceed the latest edition of “Savings By Design, Healthcare Modeling Procedures” by a minimum of 15 percent.
SECTION A6.204—PRESCRIPTIVE APPROACH
A6.204.1 ENERGY STAR equipment and appliances. All equipment and appliances provided by the builder shall be ENERGY STAR labeled if ENERGY STAR is applicable to that equipment or appliance.
A6.204.4 Commissioning. [OSHPD 1 & 4] Building commissioning shall be included in the design and construction processes of the building project to verify that the building’s energy related systems are installed, calibrated and perform according to the owner’s project requirements, basis of design and construction documents.
The owner and designer shall designate an individual as the Commissioning Authority (CxA) to lead, review and oversee the completion of the commissioning process activities. The owner shall document the Owner’s Project Requirements (OPR). The design team shall develop the Basis of Design (BOD). The CxA shall review these documents for clarity and completeness. The owner and design team shall be responsible for updates to their respective documents, develop and incorporate commissioning requirements into the construction documents and develop and implement a commissioning plan. The CxA shall verify the installation and performance of the systems to be commissioned, verify that training and operation and maintenance documentation have been provided to the owner’s operations staff and complete a commissioning report.
Commissioning process activities shall be completed for the following energy-related systems, at a minimum:
- Heating, ventilating, air conditioning and refrigeration (HVAC&R) systems (mechanical and passive) and associated controls.
- Lighting and daylighting controls.
- Domestic hot water systems.
- Renewable energy systems (wind, solar, etc.).
- Building envelope systems.
A6.204.4.1 Owner’s Project Requirements (OPR). The expectations and requirements of the building shall be documented by the owner and the designer before the design phase of the project begins. This shall be reviewed by the CxA. At a minimum, this documentation shall include the following:
- Environmental and sustainability goals.
- Energy efficiency goals.
- Indoor environmental quality requirements.
2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A6.1-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX A6.1 — VOLUNTARY STANDARDS FOR HEALTH FACILITIES [OSHPD 1, 2 & 4]
- Equipment and systems expectations.
- Building occupant and O&M personnel expectations.
CALGreen § 106.9 High relevance — show source text
FEATURE OR MEASURE COMPLIANCE LEVELS Col3 Col4 NOTES FEATURE OR MEASURE Mandatory
CALGreenVOLUNTARY
CALGreenVOLUNTARY
CALGreenVOLUNTARY
CALGreenFEATURE OR MEASURE Mandatory
CALGreenTier 1 Tier 2 Tier 2 DIVISION A6.1 – PLANNING AND DESIGN SECTION Site Development SECTION Site Development SECTION Site Development SECTION Site Development SECTION Site Development **A6.106.9 Building orientation.**Locate and orient the building as follows:
1. When site and location permit, orient the building with the long sides facing north and
south.
2. Protect the building from thermal loss, drafts and degradation of the building envelope
caused by wind and wind-driven materials such as dust. DIVISION A6.2 – ENERGY EFFICIENCY SECTION A6.203 Performance Measures SECTION A6.203 Performance Measures SECTION A6.203 Performance Measures SECTION A6.203 Performance Measures SECTION A6.203 Performance Measures A6.203.1 Energy performance. [OSHPD 1]
**A6.203.1.1 CALGreen Tier 1. [OSHPD 1]**Buildings must comply with the latest edition of
“Savings By Design, Healthcare Modeling Procedures.”
A.5.203.1.2 CALGreen Tier 2. [OSHPD 1] Buildings must exceed the latest edition of “Savings
By Design, Healthcare Modeling Procedures” by 15 percent. SECTION A6.204 Prescriptive Measures **A6.204.1 ENERGY STAR equipment and appliances.**All equipment and appliances provided
by the builder shall be ENERGY STAR labeled if ENERGY STAR is applicable to that equipment
or appliance. A6.204.4 Commissioning. Building commissioning for all building systems covered by T24,
Part 6, process systems and renewable energy systems shall be included in the design and
construction processes of the building project. Commissioning requirements shall include as
a minimum items listed in Section A6.204.4.
**A6.204.4.1 Owner’s Project Requirements (OPR).**Documented before the design phase of
the project begins the OPR shall include items listed in Section A6.204.4.
**A6.204.4.2 Basis of Design (BOD).**A written explanation of how the design of the building
systems meets the OPR shall be completed at the design phase of the building project and
updated periodically to cover the systems listed in Section A6.204.4.2.
**A6.204.4.3 Commissioning plan.CALGreen § 203.1.2.1 High relevance — show source text
In addition, a minimum of two of
the efficiency measures specified in Sections A4.203.1.2.1 through
A4.203.1.2.8 will be required to be met.
· Roof Deck Insulation or Ducts in Conditioned Space.
· High-performance Walls.
· Compact Hot Water Distribution System.
· Drain Water Heat Recovery.
· High Performance Vertical Fenestration.
· Heat Pump Water Heater Demand Management.
· Battery Storage System Controls.
· **Heat Pump Space and Water Heating.||2|2|||| |**A4.203.1.3 Consultation with local electric service provider.**Local
jurisdictions considering adoption of reduced EDR targets based on
using solar photovoltaic (PV) systems larger than required by the
California Energy Code shall consult with the local electric service
provider to ensure that that PV system sizing required to comply with
the EDR targets will be acceptable to the local electric service
provider.||2|2||||2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A4-25
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES
SECTION A4.602—RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST—continued
FEATURE OR MEASURE LEVELS
APPLICANT TO SELECT ELECTIVE MEASURESCol3 Col4 VERIFICATIONS
ENFORCING AGENCY TO SPECIFY
VERIFICATION METHODCol6 Col7 FEATURE OR MEASURE Mandatory Prerequisites and electives1 Prerequisites and electives1 Enforcing
Agency
AllInstaller or
Designer
AllThird
party
AllFEATURE OR MEASURE Mandatory Tier 1 Tier 2 Tier 2 Tier 2 Tier 2 WATER EFFICIENCY AND CONSERVATION Indoor Water Use 4.303.1Plumbing fixtures (water closets and urinals) and fittings
(showerheads, faucets and pre-rinse spray valves) installed in
residential buildings shall comply with the prescriptive requirements
of Sections 4.303.1.1 through 4.303.1.4.5. 4.303.2 Submeters for multifamily building and dwelling units in
**mixed-use residential/commercial buildings.CALGreen § 170.2 Medium relevance — show source text
A. EER2/SEER2/CEER/HSPF2 Rating. When performance compliance requires installation of a space-conditioning system with a rating that is greater than the minimum rating required by Table 170.2-K or specified for the standard
2025 CALIFORNIA ENERGY CODE 237
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
design, the installed system shall be field verified in accordance with the procedures specified in the applicable sections of Reference Residential Appendix RA3. B. Variable capacity heat pump (VCHP) compliance option. When performance compliance requires installation of a heat pump system that meets all the requirements of the VCHP compliance option specified in the ACM Reference Manual, the system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.4.4.3.
C. Low leakage air handler. When performance compliance requires installation of a low leakage air-handling unit, the installed air handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9. D. Thermal balancing valve. When performance compliance requires installation of thermal balancing valves with variable speed circulation pump(s), the installation shall meet the procedures specified in Reference Residential Appendix RA4.4.3. E. Heat pump—rated heating capacity. When performance compliance requires installation of a heat pump system, the heating capacity values at 47°F and 17°F shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.4.4.2. F. Dwelling unit enclosure air leakage. When performance compliance requires a building enclosure leakage rate that is lower than the standard design, the building enclosure shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.8. G. Quality insulation installation (QII). When performance compliance requires field verification of QII, the building insulation system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.5.
NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
SECTION 170.2—PRESCRIPTIVE APPROACH
Multifamily buildings, including both dwelling units and common use areas, that comply with the prescriptive standards shall be designed, constructed and equipped to meet all of the requirements for the appropriate climate zone shown in Table 170.2-A. In Table 170.2-A, NA (not allowed) means that feature is not permitted in a particular climate zone and NR (no requirement) means that there is no prescriptive requirement for that feature in a particular climate zone. Installed components shall meet the following requirements:
(a) Envelope component requirements .
- Exterior roofs and ceilings . Exterior roofs and ceilings shall comply with each of the applicable requirements in this subsection:
Frequently asked questions
What is the single most important compliance step for CALGreen performance?
Use Energy Commission‑certified compliance software to achieve the reduced LSC target from Table A4.203.1.1 and document that LSC on the Certificate of Compliance (see § A4.203.1.1) .
How many prerequisite measures must be implemented?
A minimum of two prerequisite measures from § A4.203.1.2 must be met and documented (see § A4.203.1.2) .
Do the Table margins replace the Energy Code?
No. The CALGreen provision requires the Certified software’s minimum LSC for Energy Code compliance be made more stringent by the Table A4.203.1.1 margin; projects still use the Energy Code compliance tools and procedures (see § A4.203.1.1) .
Can shared/community solar or storage help meet the target?
Yes—community shared renewable or BESS options that meet Title 24, Part 1, § 10‑115 can be used to achieve LSC targets as noted in the Table note (see § A4.203.1.1) .
What if a local jurisdiction hasn’t adopted Appendix A4?
These measures in Appendix A4 are voluntary unless the local jurisdiction adopts them and completes the Energy Commission/CBSC filing process required under § A4.201.1 (see § A4.201.1) .
More in California Green Building Standards Code (CALGreen)
- Administration (Chapter 1)
- Nonresidential Voluntary Measures (Appendix A5 — divisions A5.1–A5.6, electives & verification)
- Residential Mandatory Measures — Planning & Design; Energy; Water; Materials; Environmental Quality (Chapter 4)
- Definitions (Chapter 2)
- Voluntary Standards for Health Facilities (Appendix A6 / OSHPD guidance)
- Green Building – scope, mixed occupancies, phased projects (Chapter 3)
- Residential Voluntary Measures (Appendix A4 — divisions A4.1–A4.6, tiers & model ordinance)
- Nonresidential Mandatory Measures — Planning & Design; Energy; Water; Materials; Environmental Quality (Chapter 5)
- Compliance verification, construction documents & checklists (Section 102, Chapter 7, Appendix checklists)
- Referenced Organizations and Standards (Chapter 6)
- Voluntary Tiers and CALGreen Tier 1 / Tier 2 (performance tiers, thresholds)
- Installer and Special Inspector Qualifications (Chapter 7)
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