Is Title 24 the Same as CALGreen?

Call (626) 365-1518 | Alternative Energy Systems

Is Title 24 the Same as CALGreen is a common question because the terms are frequently used together during California building permit review.

The short answer is:

No, the Title 24 Energy Code and CALGreen are not the same code. However, CALGreen is one part of the larger California Building Standards Code known as Title 24.

More specifically:

• California Energy Code: Title 24, Part 6
• CALGreen: Title 24, Part 11
• Title 24: The broader California Building Standards Code containing multiple parts

This distinction matters because a project can comply with its Title 24 energy calculations and still have separate CALGreen requirements that must be addressed elsewhere in the plans and permit documents.

The Energy Code focuses primarily on building energy efficiency.

CALGreen addresses a broader group of green-building measures that can include water efficiency, construction waste, material-related requirements, indoor environmental quality, electric-vehicle infrastructure, and other sustainable building practices.

For applicable permit applications filed on or after January 1, 2026, California is using the 2025 editions of both the Energy Code and CALGreen.

Alternative Energy Systems focuses on California energy-compliance calculations and documentation associated with the Energy Code.

Call (626) 365-1518 if you need Title 24 energy calculations, a compliance report, revisions, or assistance coordinating the energy documentation with your plans.

The Important Distinction: Title 24 Is the Entire Building Standards Code

A large part of the confusion comes from the way people use the phrase “Title 24.”

In everyday construction conversations, someone may say:

“I need Title 24.”

Usually, that person means they need an energy calculation or Energy Code compliance report.

Technically, however, Title 24 is much broader.

California’s Building Standards Code is divided into multiple parts covering subjects such as:

• Administrative requirements
• Building construction
• Residential construction
• Electrical systems
• Mechanical systems
• Plumbing systems
• Energy efficiency
• Fire requirements
• Existing buildings
• Green building standards

The Energy Code is only one part of that larger system.

CALGreen is another.

What Part of Title 24 Is the Energy Code?

California’s Building Energy Efficiency Standards are primarily contained in:

Title 24, Part 6.

This is the portion commonly associated with:

• Title 24 energy calculations
• Energy compliance reports
• Building-envelope performance
• Windows
• Insulation
• HVAC systems
• Duct systems
• Ventilation
• Water heating
• Lighting
• Lighting controls
• Solar and battery requirements when applicable
• Energy-related verification requirements

When Alternative Energy Systems prepares Title 24 calculations, the work is primarily associated with Energy Code compliance rather than every requirement contained in the broader California Building Standards Code.

What Part of Title 24 Is CALGreen?

CALGreen is formally known as the California Green Building Standards Code.

It is:

Title 24, Part 11.

CALGreen contains mandatory green-building requirements for applicable projects as well as additional voluntary measures.

Depending on the project and jurisdiction, CALGreen can address subjects involving:

• Planning and design
• Water efficiency
• Material conservation
• Resource efficiency
• Environmental quality
• Construction waste
• Pollutant control
• Electric-vehicle infrastructure
• Other green-building measures

These subjects overlap with the broad goal of improving building performance, but they are not identical to the energy calculations performed under Part 6.

What Is the Main Difference Between the Energy Code and CALGreen?

The easiest way to understand the difference is by looking at their primary focus.

Title 24, Part 6: Energy Performance

The Energy Code focuses on reducing inefficient or unnecessary building energy consumption.

It can regulate or evaluate:

• Building envelope
• Insulation
• Fenestration
• Roof characteristics
• Heating
• Cooling
• Ducts
• Ventilation
• Water heating
• Lighting
• Controls
• Other energy-related systems

Title 24, Part 11: Green Building

CALGreen has a broader sustainability focus.

Its mandatory provisions can address topics beyond direct energy calculations, including:

• Water conservation
• Material conservation
• Construction waste management
• Indoor environmental quality
• Pollutant control
• Site-related measures
• Electric-vehicle infrastructure
• Other green-building practices

A project may therefore need to demonstrate compliance with both codes.

Why Are the Two Codes Often Confused?

There are several reasons.

First, both are contained within Title 24.

Second, both can affect the same building project.

Third, both are updated through California’s building-code cycle.

Fourth, some subjects can appear related.

For example:

• Energy-efficient buildings can also be considered greener buildings
• Ventilation can affect both energy performance and indoor environmental quality
• Electric vehicle infrastructure interacts with building electrical systems
• Solar and energy systems relate to broader sustainability goals

But overlap in purpose does not mean the two codes are interchangeable.

Does a Title 24 Energy Report Cover CALGreen?

Not automatically.

A Title 24 energy report prepared under Part 6 documents the applicable energy-related characteristics of the project.

That can include:

• Energy calculations
• Building-envelope measures
• Window performance
• Insulation
• Mechanical systems
• Ventilation information
• Water-heating information
• Lighting and controls when applicable

It should not be assumed to satisfy every CALGreen requirement.

CALGreen documentation may require additional information elsewhere in the plans, specifications, forms, or construction documents.

A CALGreen Checklist Is Not the Same as a Title 24 Energy Calculation

A CALGreen checklist can identify applicable green-building requirements.

That is different from an energy model or Title 24 calculation.

Energy compliance may require evaluation of variables such as:

• Climate zone
• Building size
• Orientation
• Conditioned floor area
• Window area
• Window performance
• Insulation
• HVAC efficiency
• Duct conditions
• Water heating

Checking CALGreen items does not replace that calculation.

Likewise, completing an energy model does not automatically complete the project’s CALGreen obligations.

Do Both Codes Apply to Residential Construction?

They can.

Applicable residential projects may have Energy Code requirements under Part 6 and separate CALGreen requirements under Part 11.

A new home, for example, may need energy documentation addressing:

• Walls
• Roofs
• Insulation
• Windows
• HVAC
• Ventilation
• Water heating

The same project can also have separate CALGreen requirements involving applicable green-building measures.

The project team should therefore review both parts rather than assuming one substitutes for the other.

Do Both Codes Apply to ADUs?

Depending on the ADU configuration and project scope, both Energy Code and CALGreen requirements can be relevant.

An ADU may involve energy-related analysis of:

• Conditioned floor area
• Wall assemblies
• Roof assemblies
• Windows
• Insulation
• HVAC
• Ventilation
• Water heating

Separate green-building requirements may also apply.

For more information about the energy side of these projects, review ADU Title 24.

Do Both Codes Apply to Residential Additions?

They can, depending on project size, scope, and applicable code provisions.

Energy Code requirements can be triggered when an addition creates new conditioned floor area and new building-envelope components.

CALGreen applicability should be evaluated separately.

Do not assume that because an addition requires an energy report it automatically requires every CALGreen measure, or vice versa.

Each code contains its own scope and application provisions.

Do Both Codes Apply to Remodels?

Potentially.

Existing-building work can trigger requirements under one or both codes depending on what is being altered.

A project involving:

• Windows
• HVAC equipment
• Water heating
• Lighting
• Plumbing fixtures
• Interior finish materials

may interact with different portions of California’s building standards.

The exact scope should be reviewed rather than relying on the general word “remodel.”

Do Both Codes Apply to Multifamily Buildings?

Multifamily projects can have requirements under both Part 6 and Part 11.

Energy compliance may involve:

• Building envelope
• Dwelling-unit systems
• Central systems
• Ventilation
• Water heating
• Lighting
• Solar and battery requirements when applicable

CALGreen can add separate requirements involving other green-building topics.

Multifamily projects should therefore be coordinated across the complete permit set rather than treating energy compliance as the only sustainability-related review.

Do Both Codes Apply to Commercial Buildings?

Yes, applicable nonresidential construction can involve both Energy Code and CALGreen requirements.

Part 6 may address:

• Building envelope
• Mechanical systems
• Ventilation
• Service water heating
• Interior lighting
• Exterior lighting
• Lighting controls
• Solar and battery provisions when applicable

Part 11 can address other green-building provisions.

A commercial project may therefore require coordination among:

• Architect
• Energy consultant
• Mechanical engineer
• Electrical designer
• Plumbing designer
• General contractor
• Other project professionals

For energy-related commercial assistance, review Title 24 compliance services.

What Does CALGreen Cover That the Energy Code Does Not Primarily Address?

CALGreen extends beyond building energy calculations.

Depending on building type and scope, CALGreen can include requirements involving areas such as:

• Water-efficient fixtures
• Indoor water use
• Outdoor water considerations
• Construction waste management
• Material conservation
• Low-emitting materials
• Indoor environmental quality
• Pollutant control
• Electric-vehicle charging infrastructure
• Other sustainable construction practices

These measures demonstrate why CALGreen should not be reduced to an energy-efficiency checklist.

What Does the Energy Code Cover That Is Different From CALGreen?

Part 6 focuses much more directly on quantitative building energy performance.

Energy analysis can involve:

• Climate zone
• Energy budgets
• Performance modeling
• Prescriptive energy requirements
• Wall and roof performance
• Window U-factor
• Solar heat gain coefficient
• HVAC efficiency
• Duct requirements
• Water-heating efficiency
• Lighting power
• Lighting controls

These technical calculations are central to Part 6 compliance.

Is Ventilation a Title 24 or CALGreen Requirement?

This question illustrates why the two codes can appear to overlap.

Ventilation and indoor environmental quality can interact with requirements found in different parts of California’s building standards.

Part 6 contains Energy Code ventilation requirements.

CALGreen also includes indoor environmental quality provisions.

The correct response is not to choose one code and ignore the other.

The design team should identify which specific requirement applies under each applicable code section.

Is Water Efficiency Part of Title 24 Energy Calculations?

Energy use associated with water heating is relevant to Part 6.

However, broader water-conservation requirements can be addressed elsewhere, including CALGreen and other applicable California codes.

For example:

• Water-heater efficiency can affect Energy Code compliance
• Water-efficient plumbing fixtures can involve different code requirements

These are related concepts but not the same compliance calculation.

Are Electric Vehicle Requirements Part of the Energy Report?

Do not assume every electric-vehicle requirement is included in an ordinary Title 24 energy report.

CALGreen contains important electric-vehicle infrastructure requirements for applicable projects.

Other electrical requirements can also apply.

The architect and electrical design team should coordinate these requirements within the complete permit package.

An energy consultant’s Part 6 report should not automatically be treated as the project’s complete EV-compliance documentation.

Are Solar Requirements Part of CALGreen or the Energy Code?

Applicable solar photovoltaic requirements can be contained within California’s Energy Code.

The current Energy Code includes solar-related provisions for qualifying residential, multifamily, and nonresidential projects.

CALGreen can contain related sustainability provisions, including voluntary energy-efficiency measures.

The correct requirement should therefore be identified by the specific code section rather than assuming every sustainability-related feature belongs exclusively to CALGreen.

Are Battery Requirements Part of CALGreen?

The current Energy Code contains battery-energy-storage requirements or readiness provisions for certain qualifying projects.

CALGreen may also contain related provisions within its broader green-building framework.

The applicability can vary by building type and project scope.

The project team should review both the Energy Code and CALGreen rather than assigning every battery-related issue to only one code without checking the applicable section.

What Are CALGreen Tier 1 and Tier 2?

CALGreen includes additional voluntary measures commonly organized into Tier 1 and Tier 2.

These go beyond the statewide mandatory minimum provisions.

A local jurisdiction can adopt qualifying voluntary measures and make them mandatory locally through the applicable legal process.

This means a project can encounter:

• Statewide mandatory CALGreen requirements
• Additional locally adopted green-building requirements

Do not assume that every California jurisdiction uses the same voluntary tier requirements.

Local project requirements should be checked with the applicable authority having jurisdiction.

Are All CALGreen Requirements Voluntary?

No.

This is another common misunderstanding.

CALGreen contains mandatory provisions.

It also contains additional voluntary measures.

The California Building Standards Commission describes CALGreen as California’s mandatory green-building standards code.

Tier 1 and Tier 2 contain additional voluntary provisions that can be adopted by local jurisdictions.

Therefore:

CALGreen itself is not simply an optional green-building program.

Are All CALGreen Requirements the Same Statewide?

California establishes statewide mandatory provisions, but local jurisdictions can adopt qualifying additional green-building requirements through applicable procedures.

This means the exact requirements can differ when a city or county has adopted additional measures.

The building department should be consulted when local CALGreen requirements are unclear.

Does the California Energy Commission Control CALGreen?

Not by itself.

The California Building Standards Commission has significant responsibility for CALGreen and can propose green-building standards for applicable nonresidential occupancies where another state agency does not have authority.

Other California agencies also have authority over particular building occupancies.

The California Energy Commission contributes energy-related provisions, including voluntary energy-efficiency measures contained within CALGreen.

This differs from Part 6, where the California Energy Commission is the primary state agency responsible for developing and implementing the Energy Code.

Who Enforces CALGreen?

For most ordinary projects, the applicable authority having jurisdiction—often the local city or county building department—reviews and enforces applicable CALGreen requirements as part of the permit process.

The same building department may therefore review:

• Energy Code documentation
• CALGreen requirements
• Building-code requirements
• Mechanical requirements
• Electrical requirements
• Plumbing requirements

This can make the codes appear to be one document from the applicant’s perspective even though they contain separate requirements.

Who Enforces the Energy Code?

For ordinary projects, the authority having jurisdiction also generally reviews and enforces Energy Code compliance through:

• Plan review
• Correction comments
• Permit approval
• Construction inspections
• Review of applicable compliance documentation

The fact that the same building department may enforce both Part 6 and Part 11 does not make those codes identical.

Do Title 24 and CALGreen Use the Same Forms?

Not necessarily.

Energy Code compliance can use project-specific forms documenting:

• Design compliance
• Installation
• Verification
• Acceptance testing when applicable

CALGreen documentation can use different checklists, plan notes, forms, specifications, and supporting documents.

One set of forms should not automatically be substituted for the other.

Why Do Both Codes Need to Match the Plans?

Both codes ultimately apply to the actual building being permitted and constructed.

The plans may need to communicate requirements involving:

• Insulation
• Windows
• Mechanical systems
• Ventilation
• Water heating
• Lighting
• Water conservation
• Waste management
• Low-emitting materials
• Electric-vehicle infrastructure

If separate compliance documents contradict the construction drawings, building-department corrections can result.

Can a Project Pass Title 24 Energy Compliance but Fail CALGreen Review?

Yes.

A project may have a correct Part 6 energy calculation while still having missing or incorrect Part 11 information.

For example, an energy report can correctly demonstrate:

• Window performance
• Insulation
• HVAC efficiency
• Water-heating energy performance

while the permit set could still be missing a separate CALGreen requirement.

The reverse is also possible.

A complete CALGreen checklist does not correct an inaccurate energy model.

Can a Project Satisfy CALGreen but Fail Energy Compliance?

Yes.

CALGreen compliance does not replace Energy Code compliance.

A project may satisfy applicable requirements involving waste management, materials, or water efficiency while still having an energy issue involving:

• Windows
• Insulation
• HVAC
• Ducts
• Water-heating efficiency
• Lighting power
• Energy-model results

Both applicable code paths need to be addressed.

Do the Current 2025 Codes Use the Same Effective Date?

Yes.

The current 2025 California Energy Code and 2025 CALGreen Code became effective January 1, 2026.

For applicable permit applications under the current cycle, the project team should use the correct 2025 documentation rather than forms from an earlier edition.

Are Both Codes Updated Every Three Years?

The major editions of California’s Building Standards Code follow a three-year cycle.

This keeps Energy Code and CALGreen updates aligned with the broader California building-code cycle.

Current editions include:

• 2025 Energy Code – Title 24, Part 6
• 2025 CALGreen – Title 24, Part 11

The next major code cycle will continue that triennial process.

What Happens if You Use an Old CALGreen Checklist With a New Title 24 Report?

Using documents from different code cycles can create permit-review problems.

A current project should be checked for the applicable:

• Energy Code edition
• CALGreen edition
• Building Code edition
• Local amendments
• Required forms

Do not assume that a checklist or report from an older project remains suitable simply because the new project looks similar.

How Should Architects Coordinate Part 6 and Part 11?

Architects and building designers should treat energy and CALGreen requirements as separate but coordinated parts of the permit set.

The architect may need to coordinate with:

• Energy consultant
• Mechanical engineer
• Electrical designer
• Plumbing designer
• Contractor
• Owner

This helps ensure the final drawings communicate requirements from all applicable codes rather than allowing one compliance package to contradict another.

What Should Contractors Know About the Difference?

Contractors should not assume that following the energy report automatically satisfies every green-building requirement.

During construction they may encounter requirements relating to:

• Energy-efficient products
• Insulation
• HVAC
• Ventilation
• Water conservation
• Construction waste
• Material selection
• Pollutant control
• Other project-specific measures

The approved plans and specifications should identify the requirements applicable to the actual construction.

What Should Homeowners Know?

For homeowners, the main point is simple:

A Title 24 energy report is not the complete California building-code package.

Your project may need several different types of compliance documentation.

For example, an ADU could involve:

• Architectural plans
• Structural documents
• Title 24 energy calculations
• CALGreen requirements
• Mechanical information
• Electrical information
• Plumbing information

Each document supports a different part of the permit review.

What if the Building Department Requests Both Title 24 and CALGreen Corrections?

Separate the comments by subject.

An energy-related correction may involve AES when it concerns:

• Energy calculations
• Windows
• Insulation
• HVAC information
• Water heating
• Energy forms

A CALGreen correction may need to be addressed by the architect, designer, contractor, or another project professional depending on the issue.

Send AES the complete correction notice rather than one isolated comment.

AES can identify which comments fall within the energy-compliance scope and which should be coordinated with another professional.

What Should You Send AES?

For Title 24 energy-compliance services, useful project information can include:

• Floor plans
• Exterior elevations
• Building sections
• Roof plans
• Window schedules
• Insulation details
• HVAC specifications
• Duct information
• Ventilation information
• Water-heating specifications
• Commercial lighting plans when applicable
• Building-department correction comments

Before submitting files, review what AES will need from you.

Why Choose Alternative Energy Systems?

Alternative Energy Systems provides professional Title 24 energy calculations, compliance reports, revisions, and plan-check support throughout California.

AES brings more than 30 years of California energy-compliance experience to:

• New homes
• ADUs
• Garage conversions
• Additions
• Residential remodels
• Multifamily buildings
• Mixed-use projects
• Commercial buildings
• Office tenant improvements
• Retail projects
• Restaurant projects
• Warehouse alterations
• HVAC projects
• Commercial lighting projects
• Energy-related plan-check corrections

AES focuses on the energy-compliance portion of the permit package and helps coordinate those requirements with the actual plans.

Learn more through the About Us page or review company background on the clients page.

Need Help Separating Title 24 Energy Requirements From CALGreen?

Call (626) 365-1518 | Alternative Energy Systems

Understanding Is Title 24 the Same as CALGreen becomes easier once the code structure is clear.

CALGreen is part of Title 24, but it is not the same as the Energy Code.

The practical distinction is:

• Title 24, Part 6: California Energy Code
• Title 24, Part 11: CALGreen

Part 6 focuses primarily on energy performance.

Part 11 addresses a broader range of green-building requirements.

A project can therefore need both.

Alternative Energy Systems can help with the Title 24 energy-compliance portion of your project, including:

• Energy calculations
• Compliance reports
• Energy forms
• Plan coordination
• Report revisions
• Energy-related plan-check corrections

Call (626) 365-1518 or begin through the contact page.

When service and payment have already been arranged, payment can be completed through the AES payment page.

For official information about the Energy Code, review the California Energy Commission 2025 Building Energy Efficiency Standards.

For official information about CALGreen, review the California Building Standards Commission CALGreen resources.

Frequently Asked Questions: Is Title 24 the Same as CALGreen?

Is Title 24 the Same as CALGreen?

No. CALGreen is Part 11 of the broader California Building Standards Code known as Title 24. The California Energy Code is Part 6.

Is CALGreen part of Title 24?

Yes. CALGreen is formally the California Green Building Standards Code, Title 24, Part 11.

What part of Title 24 is the Energy Code?

California’s Building Energy Efficiency Standards are primarily contained in Title 24, Part 6.

What part of Title 24 is CALGreen?

CALGreen is Title 24, Part 11.

Does a Title 24 energy report satisfy CALGreen?

Not automatically. A Part 6 energy report addresses energy compliance and should not be assumed to satisfy every Part 11 requirement.

Does a CALGreen checklist replace a Title 24 report?

No. CALGreen documentation does not replace applicable Part 6 energy calculations or compliance forms.

Can a project require both?

Yes. Many California permit projects can have both Energy Code and CALGreen requirements.

Is CALGreen mandatory?

Yes. CALGreen contains mandatory green-building requirements for applicable projects as well as additional voluntary measures.

What are CALGreen Tier 1 and Tier 2?

Tier 1 and Tier 2 contain additional voluntary green-building measures beyond statewide mandatory minimums. Local jurisdictions can adopt qualifying measures and make them mandatory locally.

Is Title 24 only about energy?

No. Title 24 is California’s broader Building Standards Code. Energy efficiency is primarily Part 6.

Is CALGreen only about energy?

No. CALGreen addresses broader green-building topics including water efficiency, materials, construction waste, indoor environmental quality, and other sustainability measures.

Does CALGreen regulate water efficiency?

Yes. Applicable CALGreen provisions include water-efficiency requirements.

Does the Energy Code regulate water heating?

Yes. Part 6 regulates applicable energy-related characteristics of water-heating systems.

Are water efficiency and water-heating efficiency the same requirement?

No. They can relate to one another but address different aspects of building performance.

Does CALGreen cover construction waste?

Yes. Applicable CALGreen provisions include material conservation and construction waste requirements.

Does the Energy Code cover construction waste?

Construction waste is not the primary focus of Part 6 energy calculations.

Does CALGreen include electric-vehicle requirements?

Yes. CALGreen contains electric-vehicle infrastructure requirements for applicable projects.

Does Title 24 Part 6 include solar requirements?

Yes. The Energy Code contains solar-related requirements for qualifying projects.

Does Part 6 include battery requirements?

The current Energy Code includes battery-storage or battery-ready provisions for certain qualifying projects.

Can energy and CALGreen requirements overlap?

They can address related building-performance goals, but the requirements remain contained in separate parts of Title 24 and should be reviewed independently.

Who develops the Energy Code?

The California Energy Commission is the primary state agency responsible for California’s Building Energy Efficiency Standards.

Who administers CALGreen?

The California Building Standards Commission and other authorized state agencies have roles in developing and administering CALGreen requirements for applicable occupancies.

Who enforces the Energy Code and CALGreen?

For most ordinary construction projects, the applicable city or county building department reviews and enforces the requirements during permitting and inspection.

What CALGreen code is currently in effect?

The 2025 California Green Building Standards Code became effective January 1, 2026.

What Energy Code is currently in effect?

The 2025 California Building Energy Efficiency Standards became effective January 1, 2026.

Can my city have stricter CALGreen requirements?

A local jurisdiction can adopt qualifying additional green-building measures through the applicable California procedures.

Can AES prepare my Title 24 energy calculations?

Yes. Alternative Energy Systems provides energy-compliance calculations, reports, revisions, and related plan-check support for applicable California projects.

Does AES handle every CALGreen requirement?

AES focuses on energy-compliance services. CALGreen items outside that energy scope may need to be addressed by the architect, designer, contractor, or another appropriate project professional.

How do I get started?

Call Alternative Energy Systems at (626) 365-1518 and provide the current plans and project information for review.