Why Every California Homeowner Needs to Understand Title 24
If you live in California and plan to upgrade your home’s insulation, replace an HVAC system, remodel, or build new construction, you will need to comply with Title 24.
Title 24 is California’s official energy code. It sets the rules for energy use in residential and commercial buildings. From attic insulation and ductwork to lighting, windows, and solar systems, Title 24 affects almost every major home upgrade in the state.
In this blog post, AtticShield breaks down everything you need to know about California Title 24 Part 6: Building Energy Efficiency Standards, including:
- What Title 24 is and why it exists
- How it impacts home upgrades
- What’s new in the 2022 and 2025 code cycles
- Attic insulation and air sealing requirements
- Title 24 permits, documentation, and compliance paths
- How AtticShield ensures your upgrades are legal and efficient
Let’s begin with the basics.
1. What Is Title 24?
Title 24 is part of the California Code of Regulations (CCR) — a set of laws that govern building safety, energy efficiency, accessibility, and more.
There are multiple parts to Title 24, but the one that affects energy use is Part 6: Building Energy Efficiency Standards.
In simple terms: Title 24 sets the energy rules for all residential and commercial buildings in California.
If you’re insulating your attic, sealing ducts, changing lighting, or replacing windows — you’ll likely need to comply with Title 24.
2. Who Enforces Title 24 and Where Does It Apply?
Title 24 is enforced by:
- Local building departments
- Certified Title 24 energy consultants
- HERS raters (Home Energy Rating System inspectors)
It applies to:
- All new construction
- Additions
- Major remodels
- HVAC and insulation upgrades that require a permit
California is the only state with its own custom energy code (Title 24) built on top of the national IECC standard.
3. What Is Title 24, Part 6?
Part 6 of Title 24 focuses specifically on energy conservation. It was first adopted in 1978 and is updated every three years.
It governs:
- Insulation (attic, walls, crawl spaces)
- Heating, ventilation, and air conditioning (HVAC)
- Water heaters
- Lighting systems
- Windows, doors, and skylights
- Solar panel requirements (in new construction)
Its goal is to help California meet aggressive energy and climate goals by reducing building-related energy usage.
4. Why Title 24 Matters for Homeowners
If you are planning to:
- Add a room or convert a garage
- Replace your attic insulation
- Install a new duct system
- Replace your HVAC system
- Replace more than 50 sq. ft. of windows
- Pull a permit for energy-impacting work
…then you are legally required to comply with Title 24.
Benefits of compliance include:
✅ Lower utility bills
✅ Better indoor comfort
✅ Increased home value
✅ Access to rebates and tax credits
✅ Avoiding penalties or failed inspections
5. Title 24 vs. IECC vs. ENERGY STAR
| Standard | Title 24 | IECC | ENERGY STAR |
|---|---|---|---|
| Type | State law | Model national code | Voluntary certification |
| Applies To | California only | Most U.S. states | U.S. homes and products |
| Enforced By | Local building officials | States/municipalities | EPA (for certification) |
| Minimum/Above-Code? | Mandatory baseline | Baseline | Above-code recommendation |
| Purpose | Climate policy + energy savings | National energy standard | Product/home efficiency label |
California’s Title 24 is more aggressive than the IECC and integrates many ENERGY STAR principles into law.
6. Title 24 Requirements for Attic Insulation
California requires high-performance attic insulation in all climate zones.
Example: Title 24 Prescriptive Attic Insulation (Zone 3/4)
| Location | Prescriptive R-value |
|---|---|
| Ceiling (Ventilated Attic) | R-38 or R-49 |
| Cathedral Ceiling | R-30 (min) |
| Roof Deck (Unvented Attic) | R-19 min (with rigid foam) |
| Duct Area | R-8 (unconditioned spaces) |
Note: The R-value must be met after compression or settling. Blown-in must be evenly distributed and properly labeled.
7. Title 24 and Air Sealing Guidelines
Before insulation is installed, homes must be properly air sealed to reduce energy waste.
Requirements include:
- Sealing top plates and ceiling penetrations
- Caulking or foaming around pipes and electrical boxes
- Gasketed attic hatches
- Sealing HVAC ducts, boots, and returns
Blower-door testing may be required for HERS verification in certain cases.
8. Title 24 and Ductwork Requirements
All ductwork must be:
- Sealed to <6% leakage (HERS verified)
- Insulated to R-8 in unconditioned spaces
- Supported and installed according to SMACNA guidelines
- Pressure-tested if new or replaced ducts exceed 40 linear feet
Failure to comply can cause a permit to fail final inspection.
9. What Changed in the 2022 Title 24 Code?
The 2022 update (effective January 1, 2023) brought the most significant changes in years.
Key changes include:
✅ Mandatory solar panels for new construction (with exceptions)
✅ Stronger insulation and HVAC efficiency requirements
✅ Heat pump space heating encouraged over gas
✅ Whole-house fan controls for night cooling
✅ Electric-ready panels in new homes
✅ Electrification incentives and performance credits
10. Looking Ahead: What to Expect from Title 24 in 2025
The 2025 Title 24 update (effective Jan 1, 2026) is expected to include:
- Full electrification pathways for all new homes
- Even higher performance targets for insulation and ducts
- Mandatory heat pump adoption in many climate zones
- More emphasis on whole-home performance modeling
- Revisions to blower-door testing thresholds
Keep an eye on 2025 pre-rulemaking updates.
11. How Title 24 Affects Remodels, Retrofits, and Permits
You’ll need to comply with Title 24 if your project:
- Affects more than 40 ft of ductwork
- Replaces more than 10% of your attic insulation
- Involves lighting upgrades or panel changes
- Includes wall/roof sheathing replacement
- Adds conditioned square footage
Title 24 compliance documentation may include:
- CF1R: Energy compliance form
- CF2R: Installation form
- CF3R: HERS verification form (for duct testing)
12. Title 24 Compliance Paths (Prescriptive vs Performance)
1. Prescriptive Path
Follow each measure exactly (e.g., R-38 insulation, 0.30 U-factor windows). Simpler, but less flexible.
2. Performance Path
Use software to model energy use. Allows for trade-offs (e.g., R-30 ceiling + higher SEER HVAC). Required for complex projects.
Your contractor or energy consultant will determine the right path.
13. How AtticShield Helps You Meet Title 24 Standards
At AtticShield, we don’t just install insulation—we ensure it’s done right and code-compliant.
We provide:
✅ Insulation that meets or exceeds Title 24 R-values
✅ Air sealing with spray foam, caulk, and gaskets
✅ Photos of work for HERS raters and inspectors
✅ Accurate material/labor breakdowns for rebate eligibility
✅ Title 24 documentation support if needed
We work with your GC, HVAC contractor, or energy consultant to ensure nothing gets flagged during final inspection.
14. Official Resources for Title 24
- California Energy Commission – Title 24 Portal
- CEC Blueprint Newsletter
- Title 24 Compliance Forms
- CEC Title 24 Training Resources
- Energy Code Ace (Training and Tools)
15. Conclusion: Title 24 Isn’t Optional—But Compliance Is Easier with AtticShield
Whether you’re upgrading insulation, replacing ducts, or remodeling your home, Title 24 is the law in California. It ensures homes are energy-efficient, healthy, and climate-conscious—but it can be complex.
The good news? You don’t have to figure it out alone.
At AtticShield, we specialize in Title 24–compliant insulation, air sealing, and duct system upgrades. We stay up to date on the latest codes and provide everything needed for inspections and incentives.
Get a Free Title 24–Compliant Estimate Today
📞 Call us at 858-402-0066
Let’s make your home more efficient—and keep it 100% compliant with California’s toughest code.
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