Title 24 Cool Roof Requirements and Compliance Guide

California’s Title 24 energy code sets standards for roof reflectance and thermal emittance to reduce building cooling loads and urban heat island effects. This guide explains Title 24 cool roof requirements, compliance paths, material criteria, installation best practices, inspection documentation, and incentives for residential and nonresidential buildings. It helps building owners, designers, and contractors meet code while maximizing energy savings and occupant comfort.

Requirement	Typical Metric	Who It Applies To
Cool Roof Reflectance	Initial Solar Reflectance ≥ 0.65 (varies)	New/Replacement Roofing
Thermal Emittance	Emittance ≥ 0.75	Low-sloped And Steep Roofs
Reflectance Index	SRI Based Values	Certain Climate Zones

What Title 24 Requires For Cool Roofs

Title 24 Part 6 establishes energy efficiency standards for roofing that change depending on climate zone, roof slope, and building type. The code focuses on minimum solar reflectance and thermal emittance or equivalent SRI values to reduce heat gain. Requirements can vary by jurisdiction and edition of the code, so verification with the current Title 24 documentation is essential.

Key Metrics: Solar Reflectance, Emissivity, And SRI

Solar reflectance is the portion of solar energy reflected by the roof, while thermal emissivity is the ability to release absorbed heat. The Solar Reflectance Index (SRI) combines both into a single number. Title 24 typically specifies minimum solar reflectance and emissivity or an SRI threshold depending on the roof type and climate.

Compliance Paths Under Title 24

There are two primary compliance routes: prescriptive and performance. The prescriptive path lists exact material performance thresholds to meet for a given climate zone. The performance path allows modeling with energy software to show that the building meets or exceeds code energy budgets. The prescriptive path is simpler; the performance path offers design flexibility.

Prescriptive Requirements For Residential Roofs

Residential projects often rely on prescriptive tables with climate-zone-specific minimums. Typical prescriptive criteria include a minimum initial solar reflectance and thermal emittance for steep-slope and low-slope roofs or a specified SRI for certain installations. New roofs and roof replacements must meet the stated values in the prescriptive tables for the project’s climate zone.

Performance Path And Modeling Considerations

The performance path uses compliance software (e.g., CBECC-Res, CBECC-Com) to model building energy use. Cool roof properties are entered as material inputs so designers can trade off measures (insulation, shading, HVAC efficiency) to meet the energy budget. This path benefits complex projects or where aesthetic or practical concerns limit prescriptive compliance.

Material Options That Meet Title 24

Materials that commonly satisfy Title 24 include reflective single-ply membranes (TPO, PVC), white or cool-tone metal roofs, reflective coatings, and cool asphalt shingles. Products should have manufacturer test data for initial and three-year aged reflectance and emissivity. Selecting materials with verified testing (ASTM, CRRC) streamlines approval.

Testing, Ratings, And Documentation

The Cool Roof Rating Council (CRRC) is an industry standard for solar reflectance and emissivity reporting. Title 24 compliance usually requires CRRC or equivalent test reports and product data sheets detailing initial and three-year values. Proper documentation must be submitted at permitting and retained for inspections.

Installation Best Practices

Correct installation preserves reflectivity and roof performance. Best practices include surface preparation before coatings, ensuring proper slope and drainage, using compatible adhesives and fasteners, and avoiding shading or debris accumulation. Skilled installers following manufacturer instructions ensure the roof delivers designed energy savings.

Maintenance To Preserve Cool Roof Performance

Reflective properties can degrade from dirt, biological growth, and wear. Scheduled maintenance—periodic cleaning with low-pressure washing and removing debris—can restore reflectivity. Coatings may be reapplied to rejuvenate performance. Maintaining the roof helps sustain energy savings and extends service life.

Benefits Of Meeting Title 24 Cool Roof Standards

Cool roofs reduce peak cooling loads, lower HVAC runtime, and improve indoor comfort in summer. They can extend roof lifespan and contribute to reduced urban heat island effects. Meeting Title 24 can also unlock utility incentives and local rebates that offset installation costs.

Incentives, Rebates, And Cost Considerations

Many utilities and state programs offer rebates for cool roofing or high-reflectance materials, and some local jurisdictions include incentives tied to energy code compliance. Initial costs vary by material; lifecycle savings from lower energy use and longer roof life often justify the investment. Evaluate available incentives and perform a simple payback or lifecycle analysis before selection.

Inspection, Permitting, And Field Verification

Inspectors verify that installed materials and documentation match permit submittals. This may include reviewing CRRC product sheets, manufacturer test reports, and on-site checks for visible compliance. Field-measured reflectance testing is sometimes required for verification. Accurate documentation and clear product labeling expedite permit approval and inspections.

Common Pitfalls And How To Avoid Them

Common issues include using products without CRRC ratings, misinterpreting climate-zone tables, neglecting aged reflectance values, and poor installation that compromises reflectivity. Avoid these by verifying product certifications, consulting the latest Title 24 tables, and hiring qualified contractors. Proactive planning and documentation prevent costly rework or compliance failures.

Design Strategies To Maximize Title 24 Compliance

Combine cool roofs with other energy efficiency measures—high-performance insulation, shading devices, high-efficiency HVAC systems, and ventilation improvements—for optimal results. In some cases, reflective roofs paired with increased insulation can allow smaller HVAC sizing under the performance path. Integrated design yields greater energy savings than single measures alone.

Special Considerations For Historic Or Aesthetic Constraints

When aesthetics or historic preservation limit white or high-reflectance surfaces, solutions include high-SRI colored products, cool roof coatings that match appearance goals, or performance-path modeling to trade measures. Documenting compromises and alternative measures helps obtain code compliance approvals.

Resources, Standards, And Tools

Useful references include the California Energy Commission Title 24 documentation, CRRC Rated Products Directory, CBECC compliance tools, and manufacturer technical guides. Utility program pages list incentives and approved products. These resources provide the test data, modeling platforms, and rebate details necessary for compliance.

Checklist For Achieving Title 24 Cool Roof Compliance

• Confirm Climate Zone And Applicable Title 24 Edition
• Choose a prescriptive or performance path and document the choice
• Select products with CRRC or equivalent ratings and obtain data sheets
• Submit required documentation with permit applications
• Ensure installers follow manufacturer instructions and best practices
• Plan for maintenance to preserve reflectivity and performance

Where To Get Professional Help

Energy consultants, licensed roofing contractors, and building code specialists can assist with product selection, Title 24 modeling, permit submittals, and inspections. Engaging experts early reduces the risk of noncompliance and optimizes cost-effectiveness. Professional guidance speeds approvals and improves long-term outcomes.

For accurate, project-specific advice, reference the latest Title 24 code documents and CRRC ratings, and contact local building departments or energy program representatives to confirm requirements and incentives for the specific project location.