Which Title 24 Energy Code Version Do I Need?

Call (626) 365-1518 | Alternative Energy Systems

Which Title 24 Energy Code Version Do I Need is usually answered by looking first at the applicable building permit application date.

For most current California projects:

Permit applications submitted on or after January 1, 2026: 2025 California Energy Code
Permit applications submitted from January 1, 2023 through December 31, 2025: 2022 California Energy Code
Permit applications submitted from January 1, 2020 through December 31, 2022: 2019 California Energy Code

For a new permit application today, the current statewide edition is the 2025 Building Energy Efficiency Standards, which became effective January 1, 2026.

The year printed on the code and the year it becomes effective are not the same thing.

That is why a document identified as the 2025 Energy Code is the current code during 2026.

The answer can become more complicated when a project has:

An older permit application
An expired permit
An existing Title 24 report
Plans originally prepared under another code cycle
Major design revisions
A building-department resubmittal
A permit application that crosses from one code cycle into another

Alternative Energy Systems brings more than 30 years of California energy-compliance experience to residential, multifamily, mixed-use, and commercial projects.

Call (626) 365-1518 if you have an older report or uncertain permit history and need help determining which energy documentation should be prepared.

The Current Title 24 Energy Code Is the 2025 Edition

For applicable permit applications submitted on or after January 1, 2026, California uses the 2025 Building Energy Efficiency Standards.

The Energy Code is primarily contained in:

California Code of Regulations, Title 24, Part 6.

For additional general background about the code itself, review the California Energy Code overview on Wikipedia.

The 2025 Energy Code applies to applicable:

New single-family construction
New multifamily construction
New nonresidential construction
Additions
Alterations

The exact requirements depend on building type, project scope, climate zone, systems being changed, and the compliance method being used.

Quick Energy Code Version Guide

Permit Application Date	Applicable Energy Code Cycle
January 1, 2026 and later	2025 Energy Code
January 1, 2023 through December 31, 2025	2022 Energy Code
January 1, 2020 through December 31, 2022	2019 Energy Code

Projects with older permit histories can involve earlier code editions.

Do not choose the code cycle simply from the date printed on the architectural drawings.

The permit history is usually more important.

Start With Three Questions

When trying to identify the correct Energy Code edition, begin with:

When was the applicable permit application submitted?
Is that permit application still active?
Is the current work still part of that same permit scope?

For a completely new permit application, the answer is generally straightforward.

For a project that began several years ago, those questions become much more important.

Why Is the 2025 Energy Code Effective in 2026?

California’s code editions are named for the code cycle rather than the first calendar year in which they are enforced.

For example:

The 2019 Energy Code became effective January 1, 2020
The 2022 Energy Code became effective January 1, 2023
The 2025 Energy Code became effective January 1, 2026

Therefore, seeing “2025” on a current Title 24 report prepared during 2026 does not mean the report is using an outdated code.

It identifies the current edition.

The Permit Application Date Usually Determines the Code Cycle

One of the most common mistakes is using the wrong project date.

The following dates do not necessarily establish the Energy Code edition:

The date the property was purchased
The date the architect began drawing
The date the contractor prepared an estimate
The date the owner approved the project
The date preliminary calculations were started
The date the first consultant was contacted

For ordinary new permit applications, the building permit application date is the key date used to determine the code cycle.

That means plans prepared near the end of one code cycle can require updating when the permit application is not submitted until the next cycle begins.

If I Submit a New Permit Application Now, Which Version Do I Need?

A new applicable permit application submitted now should use the 2025 Energy Code.

That means the project should use the appropriate current:

Energy Code requirements
Compliance forms
Prescriptive requirements
Performance requirements
Calculation procedures
Approved compliance software when performance modeling is used

Using forms from a previous project without checking their code cycle can lead to unnecessary corrections.

What if My Plans Were Drawn Under the 2022 Energy Code?

Plans can remain architecturally useful even when the applicable Energy Code changes.

However, the energy documentation may need to be updated.

If a project was designed during the 2022 code cycle but the permit application is submitted on or after January 1, 2026, the energy-related design should be reviewed under the 2025 Energy Code.

Potential updates can involve:

Calculations
Compliance software
Compliance forms
Window specifications
Mechanical assumptions
Water-heating requirements
Ventilation requirements
Other applicable measures

What if My Report Was Finished Before the New Code Took Effect?

The completion date of the report by itself does not lock in the previous Energy Code cycle.

Suppose a report was completed under the 2022 Energy Code in December 2025, but no applicable permit application was filed until February 2026.

The permit application is now occurring after the 2025 Energy Code effective date.

The old report should therefore be reviewed before submission.

Simply changing the date printed on the report does not convert it to the newer Energy Code.

An Old Report Cannot Be Updated by Changing the Cover Page

A new code cycle can change:

Calculation methodology
Standard-design assumptions
Prescriptive requirements
Mandatory measures
Compliance forms
Compliance software
Verification requirements

That means the underlying analysis may need to be recalculated.

Changing only:

The date
The code year
The cover sheet

does not establish compliance with the newer code.

What if My Permit Application Was Submitted Before January 1, 2026?

An applicable permit application submitted before January 1, 2026 may have been established under the 2022 Energy Code.

The 2022 code cycle applied to permit applications submitted from January 1, 2023 through December 31, 2025.

However, older applications need closer review when:

The application was abandoned
The application became inactive
The permit expired
The building department requires a new application
The project was substantially redesigned
The scope of work changed

When any of those conditions exists, confirm the permit status with the authority having jurisdiction before assuming that the older Energy Code still applies.

Does an Active Older Permit Automatically Change to the 2025 Energy Code?

Not simply because the calendar changed.

A project established under a valid earlier permit process can have different circumstances from a completely new application submitted after January 1, 2026.

Questions to answer include:

When was the original application submitted?
Was the application accepted?
Was the permit issued?
Is the permit still active?
Has the permit expired?
Has the construction scope materially changed?
Is a new permit application required?

The building department should confirm how it is treating the permit.

AES can then prepare energy documentation corresponding to that determination.

What if My Permit Expired?

An expired permit can create a different code-cycle issue from an active permit.

Depending on the building department, the project may require:

Permit renewal
Permit reactivation
A new permit application
Updated construction plans
Updated code compliance

If the jurisdiction requires a completely new permit application during the current code cycle, the project may need to comply with the 2025 Energy Code.

Do not automatically reuse the original calculations until the permit status has been confirmed.

What if the Building Department Requires a New Permit Application?

This can be an important dividing line.

If an old application has been closed and a new permit application is required, the new application’s date can determine the applicable Energy Code cycle.

That can mean an older project needs:

New calculations
Current forms
Updated compliance software
Updated specifications
Plan revisions

The amount of work depends on how much the code and project design have changed.

What if I Am Only Resubmitting Plan-Check Corrections?

A plan-check resubmittal is not necessarily the same as starting a new permit application.

The important question is whether the original permit application remains active.

If it does, the original code cycle may still control.

If the jurisdiction considers the project a new application, current requirements may apply.

When in doubt, ask the building department which Energy Code cycle it expects on the resubmittal.

What if I Am Revising an Issued Permit?

A revision to an active issued permit can also require project-specific review.

The applicable code treatment can depend on:

The original permit
The original code cycle
The extent of the revision
The jurisdiction’s procedures

Do not assume that every post-permit revision automatically changes the entire project to the newest code.

Likewise, do not assume a major redesign can always remain under the original analysis.

Confirm the permit status first.

Why Can’t I Choose the Older Code?

For a new permit application, the applicable Energy Code is not normally a matter of personal preference.

You generally cannot choose the previous edition simply because:

The plans were already drawn
The old calculations are finished
The previous requirements appear easier
The contractor is familiar with the old forms

The permit circumstances determine the applicable code.

An older code remains relevant when the project has a valid earlier permit status recognized by the enforcement authority.

Why Can’t I Automatically Choose the Newer Code for an Older Permit?

Changing code cycles can also create problems.

An existing project may already have:

Approved drawings
Energy calculations
Mechanical selections
Compliance forms
Plan-check approvals

prepared under a particular edition.

Moving voluntarily into another code cycle can affect all of those documents.

Coordinate with the building department before changing the Energy Code basis of an existing permit.

Why Do Energy Code Versions Matter?

California updates the Building Energy Efficiency Standards every three years.

The changes are not merely editorial.

Different code cycles can change requirements involving:

Building envelope
Insulation
Windows
Roof assemblies
HVAC systems
Heat pumps
Ventilation
Water heating
Lighting
Lighting controls
Solar systems
Battery storage
Electric readiness

A design that passed under an earlier edition should therefore not automatically be assumed to pass under the current edition.

The 2025 Energy Code Is Not the 2022 Code With a Different Date

The 2025 edition includes substantive changes affecting residential, multifamily, and nonresidential buildings.

Updated areas include provisions involving:

Heat-pump technology
Space heating
Water heating
Electric-ready construction
Ventilation
Building envelope performance
Solar photovoltaic systems
Battery-energy storage
Nonresidential mechanical systems

The correct code edition should therefore be established before final energy calculations are prepared.

Does the Compliance Software Change With the Code Cycle?

Yes.

Performance compliance software is approved for specific Energy Code editions.

The California Energy Commission approves software for the current code and specific building categories.

The approved software can vary according to:

Single-family buildings
Multifamily buildings
Nonresidential buildings
New construction
Additions
Alterations

Permit applications submitted on or after January 1, 2026 that use the performance method must use approved 2025 Energy Code compliance software.

For official information, review the California Energy Commission 2025 Energy Code Compliance Software information.

Can I Use 2022 Software for a New 2026 Permit Application?

Not when the project must demonstrate performance compliance under the current 2025 Energy Code.

Older software was designed around the requirements and calculation procedures of its own code cycle.

A previous model can sometimes provide useful background information, but the current compliance analysis needs to use an approved method for the applicable code.

Do the Compliance Forms Change Too?

Yes.

Compliance forms correspond to particular Energy Code editions.

Forms can also differ according to:

Building category
Project scope
New construction
Additions
Alterations
Mechanical systems
Lighting systems
Installation requirements
Verification requirements

An old form should not be reused solely because a project appears similar to a previous job.

Which Version Do I Need for a New Home?

For a new applicable residential permit application submitted on or after January 1, 2026, the current 2025 Energy Code applies.

Energy compliance can involve:

Building size
Climate zone
Orientation
Walls
Roof assemblies
Windows
Insulation
HVAC
Ducts
Ventilation
Water heating

The applicable forms and calculations should match the current code cycle.

Which Version Do I Need for an ADU?

A new ADU permit application submitted on or after January 1, 2026 generally uses the 2025 Energy Code.

This can include:

Detached ADUs
Attached ADUs
Garage conversions
Conversions of other existing spaces

Existing conditions can affect which requirements apply, but the applicable code cycle still needs to be established first.

For more information, review ADU Title 24.

Which Version Do I Need for an Addition?

A new applicable addition permit application submitted under the current code cycle uses the 2025 Energy Code.

The project may then demonstrate compliance through:

An applicable prescriptive approach
A performance approach
Other project-specific compliance documents

depending on the addition.

For more information about the calculations themselves, review Title 24 energy calculations.

Which Version Do I Need for a Remodel?

A remodel can trigger current Energy Code requirements when it alters regulated components.

Examples include:

Windows
Insulation
Exterior walls
Roofing
HVAC
Ducts
Water heating
Commercial lighting

The code cycle is determined by the applicable permit circumstances.

The amount of compliance documentation depends on the actual alteration scope.

Which Version Do I Need for HVAC Work?

Mechanical alterations can require current code-cycle-specific forms and requirements.

Depending on the project, that can affect:

Equipment efficiency
Equipment type
Duct systems
Controls
Airflow
Verification measures

Using an old mechanical compliance form for a current permit application can create unnecessary corrections.

Which Version Do I Need for a Multifamily Project?

Multifamily buildings have dedicated Energy Code requirements and compliance documentation.

A current multifamily permit application can involve:

New dwelling units
Common areas
Building-envelope requirements
Mechanical systems
Water heating
Lighting
Other applicable systems

The project should be classified correctly before the applicable forms or calculations are selected.

Which Version Do I Need for a Commercial Project?

New nonresidential permit applications submitted on or after January 1, 2026 use the current 2025 Energy Code for applicable work.

Commercial energy compliance can involve:

Building envelope
Storefront glazing
Mechanical systems
Ventilation
Service water heating
Interior lighting
Exterior lighting
Lighting controls

For professional assistance, review Title 24 compliance services.

Which Version Do I Need for a Commercial Tenant Improvement?

A tenant improvement can be governed by the current Energy Code even when the original building was constructed decades ago.

A current alteration may affect:

Lighting
Lighting controls
HVAC equipment
Ventilation
Water heating
Storefront glazing

The age of the original building does not automatically determine the code applied to new alteration work.

Does the 2025 Energy Code Apply to Existing Buildings?

It can apply to applicable new work performed in existing buildings.

California’s Energy Code regulates applicable:

Additions
Alterations

This does not mean every existing building must be completely upgraded whenever a new code cycle becomes effective.

The requirements attach according to the regulated construction being performed.

For example, an older building can have current Energy Code requirements for:

A new addition
A window alteration
An HVAC replacement
A tenant improvement
A lighting alteration

without requiring the entire original building to be rebuilt.

Does the Building’s Original Construction Date Determine the Version?

No.

The building may have been constructed under an older code while new work is reviewed under a current code.

A building completed in the 1980s can still have a 2025 Energy Code requirement when a new permit application involves regulated alterations during the current cycle.

The project scope and permit timing matter more than the age of the original structure.

Does the Code Version Determine Whether I Need Performance Calculations?

Not by itself.

The code version establishes which rules apply.

The project and selected compliance method determine whether compliance is demonstrated through:

Prescriptive requirements
Performance calculations
System-specific compliance documents

Two projects under the same 2025 Energy Code can use different compliance approaches.

Can I Use My Old Report as a Starting Point?

Yes, an older report can be useful background information.

It can help identify:

Previous building geometry
Previous window assumptions
Previous insulation
Previous mechanical systems
Previous compliance measures

However, AES should also receive the current plans.

The old report should not be assumed to represent the current project or current code cycle without review.

What if My Old Report and Current Plans Do Not Match?

The current design should be identified before the energy documentation is finalized.

Differences can involve:

Floor area
Room configuration
Windows
Insulation
Roof assemblies
HVAC
Water heating
Lighting

A report prepared correctly for an old design can still be incorrect for the current project.

What if the Architectural Plans and Report Show Different Code Years?

Resolve the conflict before submission.

The permit package should not contain one sheet referencing the 2022 Energy Code while the calculations and forms reference the 2025 Energy Code without a valid reason.

A mismatch may indicate:

Old plan notes
An outdated report
Old forms
A project carried forward from an earlier permit cycle
An unresolved code-transition issue

Do not simply edit the code year on one document without checking the underlying project requirements.

What if the Building Department Says I Used the Wrong Version?

Send AES:

The complete correction notice
The current plan set
The existing Title 24 report
Available permit information
Current mechanical information
Current window specifications
Other updated project specifications

AES can review the energy documentation and determine whether new calculations, forms, or plan coordination are required.

What if I See Information About the 2028 Energy Code?

Future standards can be developed and discussed before they become effective.

That does not make the future code the current enforceable edition for ordinary permit applications.

The current statewide Energy Code for applicable new permit applications is the 2025 edition.

When evaluating an online code reference, check:

The edition
The effective date
Whether it is current or proposed

rather than assuming the highest year number is the version your project should use.

Why the Code Keeps Changing

California updates its Building Energy Efficiency Standards through a three-year cycle.

Updates can reflect changes in:

Construction practices
Building technology
HVAC technology
Water-heating technology
Energy efficiency
Grid conditions
Building performance

That regular cycle is why existing energy documentation should be checked whenever a project remains inactive for several years.

What Should I Send AES if I Am Unsure Which Version Applies?

For a straightforward new project, the permit date can make the answer simple.

For an older project, send as much permit history as is reasonably available.

Helpful information can include:

Current floor plans
Previous floor plans
Existing Title 24 reports
Existing compliance forms
Permit application information
Permit number
Permit issuance information
Plan-check comments
Correction notices
Current mechanical plans
Current project specifications

AES can review the energy-documentation side of the project.

When the answer depends on whether an older permit remains legally active, the applicable building department should confirm that permit status.

Before sending documents, review what AES will need from you.

What Happens After the Correct Version Is Identified?

Once the applicable code cycle is known, AES can move forward with the appropriate compliance process.

1. Review the Current Project Scope

The actual proposed work is identified.

2. Confirm the Building Category

The project is classified as applicable single-family, multifamily, nonresidential, or another relevant category.

3. Determine the Compliance Path

AES evaluates whether the project uses applicable prescriptive, performance, or system-specific documentation.

4. Use the Appropriate Code-Cycle Documents

The calculations, forms, and software should correspond to the applicable Energy Code edition.

5. Coordinate the Results With the Plans

Energy-related measures should agree with the current construction drawings.

6. Revise the Documentation if the Design Changes

Significant changes can require the energy analysis or forms to be updated.

Why Choose Alternative Energy Systems?

Alternative Energy Systems provides professional Title 24 calculations, compliance documentation, revisions, and energy-related 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 projects
Mixed-use buildings
Commercial construction
Office tenant improvements
Retail projects
Restaurant projects
Warehouse alterations
HVAC projects
Commercial lighting projects
Older reports that need review
Energy-related plan-check corrections

AES evaluates the actual plans and available permit information rather than assuming that an older report, plan note, or previous project automatically uses the correct Energy Code edition.

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

Find Out Which Title 24 Energy Code Version Your Project Needs

Call (626) 365-1518 | Alternative Energy Systems

The simplest answer to Which Title 24 Energy Code Version Do I Need starts with the applicable permit application date.

For most projects:

January 1, 2026 and later: 2025 Energy Code
January 1, 2023 through December 31, 2025: 2022 Energy Code
January 1, 2020 through December 31, 2022: 2019 Energy Code

Older active permits, expired permits, major revisions, and projects being resubmitted can require additional review.

Alternative Energy Systems can review your current plans and existing energy documentation and prepare the appropriate compliance package once the applicable code cycle has been established.

Call (626) 365-1518, email info@title24energy.com, or begin through the contact page.

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

Frequently Asked Questions: Which Title 24 Energy Code Version Do I Need?

Which Title 24 Energy Code Version Do I Need?

For most projects, the applicable code version is determined by the permit application date. Applicable new permit applications submitted on or after January 1, 2026 use the 2025 Energy Code.

What Title 24 Energy Code is currently in effect?

The current statewide Energy Code is the 2025 California Building Energy Efficiency Standards.

When did the 2025 Energy Code become effective?

January 1, 2026.

Why is it called the 2025 Energy Code if it became effective in 2026?

2025 identifies the code edition. January 1, 2026 is the effective date.

Which code was in effect before the 2025 edition?

The previous statewide edition was the 2022 Energy Code.

When did the 2022 Energy Code apply?

It applied to applicable permit applications submitted beginning January 1, 2023 and remained the current cycle through December 31, 2025.

What came before the 2022 Energy Code?

The 2019 Energy Code became effective January 1, 2020.

Does the date my plans were drawn determine the Energy Code?

Not generally. For ordinary new permit applications, the permit application date is usually the key code-cycle date.

What if my plans were drawn in 2025 but submitted in 2026?

A new applicable permit application submitted on or after January 1, 2026 generally needs to comply with the 2025 Energy Code.

What if my report was prepared under the 2022 Energy Code but never submitted?

If the permit application is now being submitted under the 2025 code cycle, the older report should be reviewed and may require new calculations and forms.

Can I change the date on an old Title 24 report?

Changing the date does not update the underlying Energy Code calculations, software, forms, or compliance assumptions.

Does an old active permit automatically change to the newest code?

Not simply because the calendar changes. The building department should confirm the status of an older active permit.

What if my permit expired?

The jurisdiction may require renewal, reactivation, or a new permit application. A new application can potentially trigger the current code cycle.

What if I am only responding to corrections?

If the original permit application remains active, the existing code cycle may still apply. Confirm unusual situations with the building department.

What if I am revising an already issued permit?

The applicable treatment depends on the original permit, code cycle, scope of the revision, and jurisdiction procedures.

Can I choose the older Energy Code?

A new permit application generally cannot choose an older code solely because the previous requirements are preferred.

Can I voluntarily switch an older project to the newest Energy Code?

Do not change code cycles without first coordinating with the enforcement authority because the change can affect plans, calculations, forms, and specifications.

Do compliance forms change between code cycles?

Yes. Compliance forms correspond to specific Energy Code editions and project types.

Does compliance software change between code cycles?

Yes. Performance software is approved for specific Energy Code editions, occupancies, and project scopes.

Can I use 2022 software for a new 2026 permit application?

Not when the project must demonstrate performance compliance under the 2025 Energy Code.

Which code does a new home use now?

A new applicable permit application submitted on or after January 1, 2026 uses the 2025 Energy Code.

Which code does a new ADU use now?

A new applicable ADU permit application submitted during the current cycle generally uses the 2025 Energy Code.

Which code does an addition use?

The edition associated with the applicable permit application generally controls the addition’s Energy Code requirements.

Which code does a remodel use?

Applicable alterations use the code cycle associated with the permit circumstances and actual regulated scope.

Which code does an HVAC replacement use?

Applicable current mechanical alterations should use the requirements and forms associated with the applicable permit’s Energy Code cycle.

Which code does a commercial tenant improvement use?

A new applicable tenant-improvement permit application submitted on or after January 1, 2026 uses the current 2025 Energy Code for regulated work.

Does the age of the building determine the Energy Code edition?

No. An older building can have new work regulated under the current Energy Code.

Does an existing building have to be completely upgraded to the current code?

Not automatically. Current requirements apply according to the applicable addition or alteration scope.

Does the code edition determine whether I use performance or prescriptive compliance?

No. The edition establishes the requirements. The building type, scope, and selected compliance path determine the appropriate method.

What if my architect and Title 24 report list different code years?

Resolve the discrepancy before submission. The permit documents and energy documentation should correspond to the same applicable code cycle.

What if the building department says I used the wrong code?

Send AES the complete correction notice, current plans, existing report, and available permit information for review.

Is the 2028 Energy Code currently required?

No. Future standards can be under development before they become effective. The current statewide edition for applicable new permit applications is the 2025 Energy Code.

What should I send AES if I am unsure which code applies?

Send the current plans, previous Title 24 documentation, available permit information, and any building-department comments.

How do I get started?

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