When is a Title 24 Report Required?

A construction project can appear ready for permit submittal and still be stopped by one unresolved question: when is a Title 24 report required? For California property owners, contractors, architects, designers, and developers, answering that question early can prevent incomplete applications, avoidable correction notices, equipment conflicts, and expensive redesigns.

A Title 24 report is generally required when proposed work affects a building’s regulated energy performance. This may include the construction of conditioned space, an increase in floor area, a change to the thermal envelope, installation or replacement of mechanical systems, or alterations involving lighting, ventilation, water heating, solar, battery storage, or other regulated building features.

However, not every permit requires a complete performance model. Some projects need limited prescriptive forms, equipment documentation, plan notes, field verification, or acceptance testing rather than a full energy calculation. The correct answer depends on the building type, permit scope, applicable Energy Code cycle, and requirements of the reviewing jurisdiction.

If you’re wondering When is a Title 24 Report Required, Title24Energy.com provides online remote plan review and energy-compliance preparation for projects throughout California. Call or text (626) 365-1518 to have your proposed work reviewed before it reaches plan check.

When is a Title 24 Report Required for California Permits?

A report or related compliance documentation is typically required when the permitted work creates, expands, or materially alters a building feature regulated by California’s Building Energy Efficiency Standards. The requirement is driven by the actual construction scope—not simply by the project’s cost, square footage, or description on a contractor’s estimate.

The following project categories commonly require energy review:

• New single-family residences
• New multifamily buildings
• New nonresidential or commercial buildings
• Accessory dwelling units
• Room additions and building expansions
• Garage, attic, basement, or patio conversions into conditioned space
• Major residential or commercial alterations
• Changes to walls, roofs, floors, ceilings, insulation, windows, or doors
• Heating, cooling, ventilation, or duct-system work
• Domestic water-heating changes
• Commercial lighting and lighting-control alterations
• Projects involving solar photovoltaic or battery-storage requirements
• Plan revisions that change previously approved energy features

The required documentation may be a CF1R for an applicable single-family project, an LMCC form for low-rise multifamily construction, or an NRCC form for nonresidential, hotel, motel, or applicable high-rise multifamily work. Installation, verification, and acceptance documents may also be required during construction.

The Permit Application Date Determines the Code Cycle

Permit applications submitted on or after January 1, 2026, are generally reviewed under the 2025 California Energy Code. Earlier applications may remain subject to a previous code cycle, depending on their permit status and the enforcement agency’s determination.

The code cycle affects the available forms, approved compliance software, mandatory measures, field-verification terminology, and technical requirements. An old report should not be reused for a new permit without confirming that the code cycle, project address, climate zone, design, and construction scope still match.

A Full Report Is Not the Only Possible Requirement

People often use “Title 24 report” as a general term for all energy-compliance paperwork. In practice, the building department may require different levels of documentation.

A small alteration may need only prescriptive forms and plan notes. An HVAC replacement may require equipment documentation and Energy Code Compliance verification. A new residence or large addition may require a complete performance model. A commercial lighting alteration may require lighting compliance and acceptance-test documentation without requiring a whole-building energy model.

The safest approach is to review the complete scope before deciding that a report is—or is not—necessary.

New Construction Normally Requires a Title 24 Report

Newly constructed conditioned buildings generally require energy-compliance documentation as part of the permit package. The project must demonstrate that the proposed envelope, mechanical systems, ventilation, water heating, lighting, controls, and other regulated features comply with the applicable standards.

New Single-Family Homes

A new single-family residence typically requires a design-stage Certificate of Compliance. The analysis may account for:

• Conditioned floor area and building orientation
• Wall, roof, ceiling, floor, and slab assemblies
• Insulation values and installation requirements
• Window area and performance values
• Heating and cooling equipment
• Duct design and location
• Whole-building ventilation
• Domestic water heating
• Solar photovoltaic requirements
• Battery-storage or electric-ready measures when applicable
• Required field verification and diagnostic testing

The resulting documentation must correspond with the architectural and mechanical plans. A passing model does not eliminate corrections when the modeled building differs from the building shown on the permit drawings.

New Multifamily Buildings

Multifamily documentation depends partly on the building classification. Low-rise multifamily projects use the applicable LM document series, while certain high-rise multifamily projects use forms associated with the nonresidential standards.

These projects may require separate coordination for dwelling units, common areas, central water heating, ventilation, lighting, mechanical equipment, solar systems, and battery-storage features. Early energy review is especially valuable when several design disciplines are contributing to the permit package.

New Commercial and Nonresidential Buildings

New commercial buildings normally require documentation addressing the envelope, mechanical systems, ventilation, lighting power, lighting controls, electrical systems, water heating, and other applicable features.

The project may also require commissioning information, mechanical acceptance testing, lighting-control acceptance testing, or documentation for covered processes. These obligations should be identified during design rather than discovered shortly before final inspection.

When is a Title 24 Report Required for an Addition?

A room addition or building expansion normally requires energy-compliance review because it creates new conditioned floor area and expands the building’s thermal envelope. The new walls, roof, floor, windows, doors, lighting, ventilation, heating, cooling, and water-heating features must be evaluated under the applicable standards.

The required analysis may also include the existing building when the project connects new equipment to existing systems or modifies features outside the addition. For example, replacing the existing HVAC system to serve both the original home and a new room can broaden the energy scope beyond the newly constructed area.

Common Addition Projects

• Bedroom and bathroom additions
• Kitchen expansions
• Family-room additions
• Second-story additions
• Attached accessory dwelling units
• Conditioned sunrooms
• Home-office expansions
• Commercial building expansions

The report should be prepared from the current permit-intent plans. Changes to floor area, window size, ceiling height, insulation, or mechanical design can affect the calculations and may require updated forms.

When is a Title 24 Report Required for an ADU?

A newly constructed accessory dwelling unit generally requires residential energy-compliance documentation. This applies to detached ADUs, attached additions, and many conversions that create a separate conditioned dwelling space.

The scope may include the ADU’s envelope, glazing, HVAC system, ventilation, water heating, lighting, and other mandatory features. Solar and battery requirements depend on the project configuration, code provisions, and any applicable exceptions.

Garage and Accessory-Space Conversions

A garage or storage building may have been constructed as unconditioned space. Converting it into a dwelling unit, bedroom, office, studio, or other conditioned occupied area changes how the structure is evaluated.

The proposed conversion may need:

• New wall, roof, and floor insulation
• Compliant windows and exterior doors
• Air-sealing details
• Heating and cooling equipment
• Whole-building ventilation
• Local exhaust ventilation
• Domestic hot-water documentation
• Electrical and lighting measures
• Energy Code Compliance verification

Because conversion projects begin with existing construction, the plans should clearly distinguish existing components from new or altered work.

When Remodels Trigger Energy Documentation

A remodel does not automatically require a full energy model, but it may trigger compliance obligations when regulated components are added, replaced, or altered. The correct documentation depends on the work shown in the permit scope.

Kitchen and Bathroom Remodels

A finish-only remodel involving paint, cabinets, countertops, flooring, and similar cosmetic work may not require a complete report. Requirements can change when the project includes new lighting, ventilation, exterior windows, water-heating equipment, mechanical changes, wall reconstruction, or an increase in conditioned area.

Interior Alterations

Moving interior partitions without changing regulated systems may have limited energy impact. However, an interior alteration can require documentation when it changes lighting controls, ventilation, equipment zoning, ductwork, conditioned space, or the use and occupancy of the area.

Major Whole-Building Renovations

A substantial renovation that replaces multiple envelope and mechanical components may require a more comprehensive analysis. Evaluating the combined scope is important because several individually modest changes can create meaningful energy requirements when performed under one permit.

Window and Door Replacement Requirements

Replacing windows or exterior glazed doors can trigger California energy requirements even when the openings remain the same size. The products may need to satisfy applicable U-factor and solar heat gain coefficient limits, and their performance ratings should be documented accurately.

Not every replacement-window permit requires a complete modeled report. Some projects can demonstrate compliance prescriptively through product specifications and applicable forms. A larger alteration, change in window area, or project using performance trade-offs may require additional calculations.

Why Window Schedules Matter

The energy documents, elevations, floor plans, and window schedule should agree on the number, size, orientation, and performance of the proposed windows. Mismatched glazing information is a common reason for correction notices.

HVAC Replacement and Mechanical Alterations

Heating, cooling, ventilation, and duct-system work frequently triggers energy documentation, but the required package varies by project. A replacement system may require equipment-efficiency information, sizing or design data, duct requirements, control information, and field verification.

Mechanical Work That May Trigger Requirements

• Replacing a furnace, heat pump, or air conditioner
• Installing a new space-conditioning system
• Adding or replacing ductwork
• Relocating ducts into an attic or other unconditioned area
• Converting from one fuel source or system type to another
• Adding conditioning to previously unconditioned space
• Changing ventilation equipment
• Installing equipment as part of an addition or ADU

For projects under the 2025 Energy Code, required residential field verification and diagnostic testing use the Energy Code Compliance program. Older projects may retain HERS terminology on their approved forms.

Roofing, Insulation, and Building-Envelope Work

Reroofing does not always require a complete Title 24 performance report. However, the project may be subject to roof-product, insulation, assembly, or other prescriptive requirements depending on the building type, roof construction, climate zone, and extent of the work.

Projects that open wall or roof assemblies, replace insulation, reconstruct exterior walls, or modify conditioned-space boundaries deserve a project-specific review. The permit plans should identify the affected assemblies and the proposed thermal values.

When is a Title 24 Report Required? Creating a New Thermal Boundary

Converting an attic, garage, basement, porch, or accessory structure into conditioned space creates or modifies the thermal boundary. This type of work generally requires more extensive documentation than a routine repair because the project must establish compliant envelope assemblies and mechanical systems for the newly conditioned area.

Commercial Projects That Require Title 24 Documentation

Commercial energy requirements can be triggered without constructing an entirely new building. Tenant improvements, office renovations, retail buildouts, restaurant alterations, warehouses, medical suites, and industrial spaces may require nonresidential compliance documentation.

Commercial Lighting Alterations

Lighting projects may need documentation for lighting power, fixture wattage, automatic shutoff, occupancy controls, daylighting controls, dimming, zoning, and outdoor lighting. Applicable systems may also require acceptance testing.

Commercial Mechanical Alterations

Replacing or modifying commercial HVAC systems can involve equipment efficiency, economizers, ventilation, controls, duct systems, commissioning, and acceptance testing. The mechanical schedule and compliance forms must describe the same proposed equipment.

Commercial Tenant Improvements

A tenant improvement does not automatically require whole-building performance modeling. The required documents are based on the systems and components being altered. A limited interior project may need lighting or mechanical forms, while a larger renovation can require envelope and performance documentation as well.

Projects That May Not Need a Full Title 24 Report

Some work may fall outside full energy-modeling requirements when it does not create conditioned space or alter a regulated energy component. Examples may include limited cosmetic improvements, ordinary maintenance, certain unconditioned accessory buildings, or minor repairs.

That does not mean every such project is automatically exempt. The building department may still request product information, applicable prescriptive forms, or plan notes explaining the energy treatment.

Review what projects are exempt from Title 24 requirements for a closer look at repairs, unconditioned structures, historic-building considerations, and other potential exceptions.

Why the Requirement Should Be Confirmed Before Plan Check

Waiting for the building department to identify missing energy documentation can place the project behind schedule. The plans may need to be returned to the designer, mechanical equipment may need to be reselected, or the project may need calculations that could have been completed before submission.

An early review helps answer four practical questions:

• Does the proposed scope trigger energy compliance?
• Is a full performance report needed?
• Which forms must be included with the permit package?
• Which installation, verification, or acceptance documents will be required later?

Once those questions are resolved, the design team can coordinate the energy requirements with the plans instead of reacting to them after corrections arrive.

What Happens When a Required Report Is Missing?

A missing or incomplete report can result in a plan-check correction, delayed permit approval, inconsistent construction documents, equipment substitutions, added consultant work, or problems during inspection.

The permit reviewer may request:

• A Certificate of Compliance
• Approved software output
• Revised window or insulation information
• Mechanical equipment documentation
• Lighting and control forms
• Solar or battery information
• Mandatory-measures notes
• Identification of required field verification
• Acceptance-testing documents
• Updated forms matching the latest plan revision

Submitting coordinated documentation the first time is usually more efficient than correcting a package built from incomplete assumptions.

How Title24Energy.com Reviews Your Project

Title24Energy.com offers an online remote process designed to help permit applicants move from uncertainty to a clear documentation plan. There is no need to guess whether the project needs a full report, limited forms, or additional testing coordination.

Step 1: Submit the Current Plans

Provide the latest floor plans, elevations, sections, window schedule, mechanical information, equipment specifications, lighting plans when applicable, and any correction notice already issued by the building department.

Step 2: Confirm the Permit Scope

The review identifies what is new, existing, altered, replaced, converted, or removed. Clearly defining the scope prevents unrelated parts of the property from being included unnecessarily while ensuring that all regulated work is addressed.

Step 3: Identify the Required Documentation

The building classification, code cycle, conditioned area, envelope work, mechanical systems, lighting, water heating, and other features are reviewed to determine which compliance documents may be required.

Step 4: Coordinate the Report With the Plans

When calculations are needed, the proposed design is evaluated using the appropriate compliance method and approved tools. The resulting information should match the latest permit-intent drawings.

Step 5: Address Revisions Before Resubmittal

If the design changes or the building department issues energy-related comments, the affected documentation can be reviewed against the revised plans. This helps prevent the next submittal from combining updated drawings with outdated energy forms.

Information to Send for a Requirement Review

The following information helps produce a faster and more useful assessment:

• Project address
• Building type and current use
• Detailed proposed scope of work
• Latest architectural plans
• Existing and proposed floor areas
• Window and exterior-door information
• Insulation and assembly details
• HVAC and ventilation information
• Water-heating information
• Commercial lighting plans when applicable
• Solar and battery information when applicable
• Permit application date or intended submission date
• Building-department correction notices

Property owners who need to understand the paperwork that follows the initial determination can review the Title 24 Compliance Documentation Requirements Guide.

Find Out What Your Permit Package Needs

Knowing when is a Title 24 report required before permit submission gives you time to coordinate the calculations, plans, equipment, and supporting forms properly. It also allows contractors and designers to understand which energy measures must remain in the project as it moves from design into construction.

Title24Energy.com helps California permit applicants identify the appropriate compliance path without relying on generic assumptions. Whether the project involves a new home, ADU, addition, conversion, remodel, HVAC replacement, multifamily development, or commercial tenant improvement, the first step is a review of the actual proposed work.

Call or text (626) 365-1518 to request an online remote project review. You can also submit the current plans and project details through the Title24Energy.com contact page.

Do not let an unanswered compliance question become a permit correction. Get the requirements identified before the plans enter review and move forward with a clearer, better-coordinated submittal.

Understanding California Energy Compliance

The statewide standards commonly called Title 24 are formally contained in the California Energy Code. They regulate the energy-related design and construction of residential and nonresidential buildings, additions, and applicable alterations.

The standards are updated periodically, so project teams should use forms, software, and technical assumptions approved for the code cycle governing the permit application.