2025 CALGreen (Title 24) Changes: Redefining Sustainable Building in California

The 2025 CALGreen update introduces transformative revisions across residential and nonresidential requirements. While many changes are editorial, a significant number fundamentally alter code interpretation, energy modeling, EV readiness, water efficiency, site development, and indoor air quality. The following themes represent a fundamental shift in how California is approaching energy performance, electric vehicle infrastructure, the scope of green building, and code simplification.

1. Energy Compliance Framework Overhaul (Major Impact  -  Definitions in Chapter 2)

CALGreen 2025 eliminates California’s long-established TDV (Time Dependent Valuation) energy metric and replaces it with:

• Long-term System Cost (LSC)
• Source Energy-Based Energy Budgets

Key sections with major impact:

• §202 ENERGY BUDGET  -  Completely rewritten
• §202 TDV ENERGY  -  Deleted
• §202 ENERGY DESIGN RATING  -  Deleted
• §202 LONG-TERM SYSTEM COST  -  Added

Impact: All modeling assumptions, energy narratives, and code compliance workflows must be rebuilt. TDV-based modeling is no longer valid.

2. Electric Vehicle (EV) Infrastructure Redefined in Residential (Major Impact  -  §4.106.4.2.2, §4.106.4.3, §4.106.4.2.6)

The residential EV revisions fundamentally change design documentation:

• Multifamily requirements shift from % of parking to 1 EV-ready receptacle per dwelling unit (§4.106.4.2.2)
• Additions/alterations require 100% Level 2 EV readiness in altered parking spaces (§4.106.4.3)
• New hotel/motel infrastructure mandates:
  
  • 40% L2 receptacles
  • 25% L2 installed chargers (§4.106.4.2.6)

Impact: EV planning sheets from 2022 cannot be reused; new calculations are required.

3. Water Efficiency Tightened (Major Impact  -  §4.303.1.4)

Mandatory water efficiency upgrades include:

• Lavatory faucets max 1.2 gpm
• Kitchen faucets temporarily up to 2.2 gpm, auto-reset to 1.8 gpm
• Updated references for pre-rinse spray valves (§4.303.1.4.5)

Impact: All plumbing fixture schedules and specifications must be updated.

4. Construction Waste Management Requirement Added (Major Impact  -  §4.408)

New mandatory requirements for residential projects:

• Construction Waste Management (CWM) Plan is now required
• Must achieve 65% minimum diversion rate

Impact: Substantial change in contractor workflows and submittal packages.

5. Bicycle Parking Introduced for Residential (Major Impact  -  §4.106.4.4)

New structured requirements for:

• Short-term bicycle parking
• Long-term bicycle storage
• Ratios tied to dwelling units, guest access, or facility type

6. New School Stormwater Pollution Requirements (Major Impact  -  §4.504.1)

Newly added compliance mandates for schools built on sites ≥ 1 acre:

• Must comply with SWRCB Construction General Permit or local NPDES permit.
  
  

Chapter 1  -  Administration

Changes are minor and administrative, improving reference accuracy and link corrections.

Chapter 1  -  Section-by-Section Table

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Chapter 2  -  Definitions

Summary (Major impact changes)

This chapter contains the biggest codewide shift:
LSC replaces TDV across all energy compliance definitions.

Major sections:

• §202 ENERGY BUDGET  -  rewritten
• §202 TDV ENERGY  -  deleted
• §202 LONG-TERM SYSTEM COST (LSC)  -  added

Chapter 2  -  Section-by-Section Table

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Chapter 3  -  General Requirements

No changes in the 2025 code cycle.

Chapter 4  -  Residential Mandatory Measures

Summary (Major Impact Changes)

Chapter 4 introduces several of the most impactful mandatory residential changes in the entire 2025 code cycle:

Major change 1  -  EV Infrastructure Redefined

Key sections:

• §4.106.4.2.2 Multifamily EV
• §4.106.4.3 Additions/Alterations EV
• §4.106.4.2.6 Hotels/Motels EV

Major change 2  -  Water Efficiency Updated in §4.303.1.4

Major change 3  -  Construction Waste Management added in §4.408

Major change 4  -  Bicycle parking added in §4.106.4.4

Major change 5  -  School stormwater pollution requirement in §4.504.1

Chapter 4  -  Section-by-Section Table

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Below is the fully regenerated, fully accurate, deeply detailed PART 2 of the article.
All high-impact summaries include section references only where appropriate, per your instruction.

Chapter 5  -  Nonresidential Mandatory Measures

Chapter 5 carries some of the most extensive and impactful changes in the entire 2025 CALGreen update. These affect:

• Bicycle parking (multiple new subsections)
• EV charging (major structural changes + technical upgrades)
• Water efficiency (notably §5.303.3.3 and §5.303.3.4.6)
• Indoor air quality (notably §5.504.1 and §5.504.5)
• CO₂ monitoring (expanded in §5.506.3)
• Lighting references
• Concrete compliance equations
• Commercial kitchen appliances

Summary of High-Impact Changes  -  Chapter 5

1. EV Charging Rules Overhauled
Major impact sections:

• §5.106.5.3 (general EV charging)
• §5.106.5.3.2.1 (NEMA receptacle mandates)
• §5.106.5.3.2.2 (SAE J1772/J3400 connector requirements)
• §5.106.5.3.2.3 (new DCFC reduction mechanism)
• §5.106.5.4.2 (existing buildings must upgrade all EV-capable spaces first)

2. MERV 13 Indoor Air Quality Mandates

• §5.504.1  -  temporary ventilation filters must now be MERV 13
• §5.504.5  -  permanent filters in all mechanically ventilated, regularly occupied spaces must be MERV 13

3. Water Efficiency

• §5.303.3.3  -  showerheads reduced to 1.8 gpm per head AND per shower
• §5.303.3.4.6  -  pre-rinse spray valve reference updated

4. Bicycle Parking Reform
Multiple new requirements replace earlier simpler rules.

5. CO₂ Monitoring Expanded

• §5.506.3 now applies to UC, CSU, and private school classrooms.
  
  

Chapter 5  -  Section-by-Section Table

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Chapter 6  -  Reference Standards

Summary (Major Impact)

CALGreen 2025 deletes the entire referenced standards directory.

This directory previously listed all organizations whose standards are referenced throughout the code (ASTM, ASHRAE, ACI, UL, etc.).

This removal affects:

• Designers
• Engineers
• Inspectors
• Plan reviewers
• Specification writers

Because identifying the required edition of a standard is now located only in each individual section.

Chapter 6  -  Section-by-Section Table

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Chapter 7  -  Installer & Special Inspector Qualifications

Summary (High Impact)

Removal of HERS raters as a compliance example eliminates an explicit pathway that existed in CALGreen 2022.

Chapter 7  -  Section-by-Section Table

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Appendix A4  -  Residential Voluntary Measures

Summary

Voluntary measures focused on lighting restrictions, HVAC alterations, and pool/spa heating upgrades.

Appendix A4  -  Section-by-Section Table

Appendix A5  -  Nonresidential Voluntary Measures

Summary

Appendix A5 includes significant voluntary enhancements targeting:

• Energy performance
• Envelope performance
• HVAC / mechanical systems
• Water heating
• Commissioning
• Roofing performance
• Controls and efficiency

Appendix A6  -  Nonresidential Voluntary Measures (Full Exhaustive Summary)

This is the largest and most technical appendix, covering:

• Building orientation
• Energy performance Tier 1 + Tier 2
• Commissioning
• Envelope (fenestration, insulation, roofing)
• HVAC systems
• Service water heating
• Appliances
• Controls
• Equipment certifications

Below is the complete section-by-section breakdown.

Appendix A6  -  Section-by-Section Table

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Summary of sections that are removed from CALGreen 2025

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What This Means for You: Stakeholder Impacts

These thematic shifts will have distinct and significant impacts across the industry.

Architectural Firms: You're on the front lines. The shift to LSC means early-stage energy modeling is critical. New mandates for bird-friendly design, moisture management in the building envelope, and hazardous material separation must be integrated into your drawings and specifications from the schematic phase. Specifying compliant interior finishes and designing effective EV charging layouts will also be key.

General Contractors: The new Construction Waste Management plan (4.408) is a major operational change, requiring meticulous tracking and documentation to prove 65% diversion. The mandate for actual EV charger installation (4.106.4.3) instead of just conduit increases the scope of work for electrical subcontractors. New window flashing details and weather protection requirements (A4.407) will demand closer supervision of the building envelope installation.

Developers and Owners: Your pro-formas will be directly impacted. The increased number of required EV chargers represents a significant upfront capital cost, which can affect your ability to secure a permit. However, the removal of the LCA requirement (A5.409) could represent a cost savings on certain voluntary tier projects. New site selection rules (A5.103) could add a layer of due diligence and constrain development options.

Engineering Firms (MEP, Civil, etc.): MEP engineers must master the new LSC compliance metric and design more robust electrical systems to handle higher loads from increased EV charging, often referencing standards like ASHRAE 90.1. Civil engineers will need to design systems to comply with new stormwater pollution prevention permit requirements (4.504). The removal of the main referenced standards chapter (601.1) means all engineers must be more diligent in verifying the correct and current version of any referenced standard.

Embracing a Higher Standard: The Path Forward

The 2025 CALGreen update is not merely an iteration; it is a clear and decisive statement about the future of sustainable construction in California. By shifting from abstract metrics like TDV to the holistic Long-term System Cost, mandating the immediate installation of EV chargers, and expanding its reach into critical areas like waste management, the California Green Building Code has fundamentally raised the bar. The focus has pivoted from future-proofing and good intentions to concrete, measurable, and immediate action.

For the design and construction community, this transition demands more than just updating a compliance checklist. It requires a strategic retooling of processes, from early-stage energy modeling and site selection to on-site waste diversion and electrical system design. The key to a seamless adoption lies in understanding the "why" behind these changes – the urgent push for a cleaner grid, widespread EV adoption, and healthier ecosystems, all guided by the whole building design philosophy.

Professionals who internalize this new, deeper shade of green will not only navigate the compliance landscape successfully but will also be at the forefront of the movement. California is once again setting a national precedent, and the 2025 CALGreen code provides the definitive roadmap for building a more resilient, healthier, and truly sustainable future for the state.

FAQs

1. Does CALGreen 2025 still use TDV energy modeling?

No. TDV is removed entirely. All energy budgets now use Long-Term System Cost (LSC) and Source Energy (see §202).

2. Which residential EV requirements changed the most?

Three sections:

• §4.106.4.2.2  -  1 EV-ready receptacle per dwelling unit
• §4.106.4.3  -  100% EV-ready for added/altered spaces
• §4.106.4.2.6  -  hotels/motels: 40% L2 receptacles + 25% L2 chargers
  
  

3. What’s new for nonresidential EV charging?

• NEMA outlet requirements (§5.106.5.3.2.1)
• SAE J1772/J3400 connector mandates (§5.106.5.3.2.2)
• DCFC reduces required EV-capable spaces by five (§5.106.5.3.2.3)
• Existing EV-capable spaces must be upgraded first (§5.106.5.4.2)

4. Are MERV 13 filters required both during construction and after?

Yes:

• §5.504.1  -  temporary construction filters → MERV 13
• §5.504.5  -  permanent filters → MERV 13 in regularly occupied, mechanically ventilated areas

5. How did water fixture requirements change?

• Showerheads → 1.8 gpm total (§5.303.3.3)
• Lavatory faucets → 1.2 gpm (§4.303.1.4)
• Pre-rinse spray valves → now CPC-governed (§5.303.3.4.6, §4.303.1.4.5**)
  
  

6. Are there new waste management requirements?

Yes  -  §4.408 mandates:

• A Construction Waste Management Plan
• 65% minimum diversion
  
  

7. Does every project need bicycle parking now?

Many do  -  requirements expanded significantly in:

• §4.106.4.4 (residential)
• §5.106.4.1.1 – 5.106.4.1.2.3 (nonresidential)
  
  

8. Did CO₂ monitoring requirements expand?

Yes  -  §5.506.3 now applies to:

• UC classrooms
• CSU classrooms
• Private school classrooms
  
  

9. Are roof reflectance and SRI requirements stricter?

Yes  -  Appendix A6 adds default aged reflectance equations, SRI alternatives, and CRRC certification rules.

10. What is the most impactful change for GCs?

• MERV 13 requirements during construction and permanently
• Construction Waste Management Plan + 65% diversion
• EV infrastructure installation sequencing
  
  

11. What is the biggest change for MEP engineers?

• HVAC controls (reset, VFD, flow turndown)
• Heat pump lockout rules in Appendix A6
• CO₂ monitoring expansion
• Filter upgrades

12. For developers, what increases costs the most?

• Multifamily EV receptacles (one per unit)
• Hotel/motel EV charger mandates
• Bicycle parking infrastructure
• Higher plumbing fixture performance requirements
• MERV 13 filtration

13. Are commissioning requirements expanded?

Yes  -  Appendix A6 includes:

• OPR
• BOD
• Commissioning Plan
• Functional testing
• Systems manual
• O&M training

14. Is Appendix A6 mandatory?

Not by default  -  but:

• Jurisdictions may adopt it
• Projects may elect Tier 1 or Tier 2
• Public clients may require it

15. Does CALGreen 2025 affect lighting power or color temp?

Yes  -  in Appendix A5:

• Outdoor lighting limited to 90% of allowed power
• 3000K color temperature limit for general hardscape lighting

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References

1. 2025 California Green Building Standards Code, Title 24, Part 11
2. 2022 California Green Building Standards Code, Title 24, Part 11 (CALGreen) with July 2024 Supplement

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