Is QII Required in California?
Call (626) 365-1518 | Alternative Energy Systems
Is QII Required in California depends on the building type, project size, Energy Code version, and whether the project uses the prescriptive or performance compliance method.
For projects subject to the 2025 California Building Energy Efficiency Standards, Quality Insulation Installation is a prescriptive requirement for many residential projects, but it is not a universal requirement for every permit in the state.
For single-family residential construction, the 2025 prescriptive requirements call for QII in all California climate zones for newly constructed buildings and additions greater than 700 square feet.
That does not mean QII must always be used when a project demonstrates compliance through the performance method. Under performance compliance, QII can be traded off against other energy-efficiency measures. When verified QII is not used, the approved compliance software reduces the modeled effectiveness of applicable insulation in the proposed design.
QII can also apply differently to:
- New single-family homes
- Detached ADUs
- Attached ADUs
- Residential additions
- Residential alterations
- Low-rise multifamily buildings
- Performance-compliance projects
The answer should therefore come from the project’s actual Certificate of Compliance rather than from a general assumption that every insulated building needs third-party QII verification.
Alternative Energy Systems provides Title 24 calculations and California energy-compliance documentation for residential, multifamily, mixed-use, and commercial projects. AES can review the plans and compliance documentation to determine whether QII is included in the approved energy design.
Call (626) 365-1518 if QII appears on your plans, energy report, or correction notice and you need help understanding what is required.
What Does QII Mean?
QII stands for Quality Insulation Installation.
It is a California Energy Code compliance measure intended to verify that insulation and associated air barriers are installed according to specific quality requirements rather than assuming that the nominal insulation R-value alone represents actual building-envelope performance.
QII can address conditions involving:
- Wall insulation
- Ceiling insulation
- Roof insulation
- Raised-floor insulation
- Air barriers
- Air-sealing details
- Insulation around wiring
- Insulation around plumbing
- Insulation around electrical boxes
- Hard-to-access framing cavities
- Kneewalls
- Skylight shafts
- Attic conditions
For general background about the role insulation plays in reducing building heat transfer, review building insulation on Wikipedia.
Why Does California Have QII Requirements?
The thermal performance of insulation depends heavily on how it is installed.
A wall cavity can contain insulation labeled with the correct R-value and still perform worse than expected if the insulation contains:
- Large gaps
- Voids
- Excessive compression
- Poor fitting around pipes
- Poor fitting around wiring
- Missing areas behind obstructions
- Disconnected air barriers
QII is intended to connect the energy calculation with actual field installation quality.
QII Is More Than an Insulation Label Check
A QII inspection is not simply a matter of confirming that the installer purchased insulation with the R-value shown on the plans.
The applicable procedures can examine whether the insulation:
- Fills the intended cavities
- Fits around penetrations
- Remains in contact with applicable air barriers
- Avoids unacceptable gaps
- Avoids unacceptable voids
- Avoids improper compression
- Matches the approved compliance documentation
This is why QII involves field verification during construction.
QII Is a Prescriptive Requirement for New Single-Family Construction
The 2025 Energy Code Applies the Requirement Across California Climate Zones
For newly constructed single-family residential buildings using the 2025 prescriptive compliance approach, QII is included in the prescriptive requirements in all California climate zones.
The California Energy Commission’s 2025 Single-Family Residential Compliance Manual states that the prescriptive requirements call for QII in all climate zones for newly constructed buildings and additions greater than 700 square feet.
This means a new home following the prescriptive package should be designed and constructed with the applicable QII requirements incorporated into the project.
Does Climate Zone Eliminate QII for a New Single-Family Home?
Not under the standard 2025 single-family prescriptive requirement.
California contains 16 building climate zones, but the current single-family prescriptive QII requirement applies across those climate zones for newly constructed buildings.
Climate zone still affects many other Title 24 measures, including:
- Roof assemblies
- Window performance
- HVAC requirements
- Cool-roof provisions
- Other prescriptive envelope measures
For more information about those regional differences, review why Title 24 standards vary by climate zone.
What Parts of a New Home Does QII Cover?
For applicable new-construction QII projects, current California procedures can apply to the building envelope as a whole.
That can include applicable:
- Roof and ceiling assemblies
- Exterior walls
- Floors
- Attic assemblies
- Other boundaries between conditioned and unconditioned space
The detailed verification criteria depend on the construction assembly.
Who Verifies QII on a Current Project?
Current 2025 Energy Code projects use the Energy Code Compliance Program for required field verification and diagnostic testing.
An appropriately qualified ECC Rater performs the third-party verification required by the current compliance process.
The California Energy Commission replaced the Energy Code field-verification portion of the older HERS Program with the ECC Program beginning with the 2025 Energy Code. Older code-cycle documents can continue to use HERS terminology.
Does the Building Inspector Perform QII Verification?
The building department and third-party Energy Code rater perform different functions.
When a project requires ECC field verification of QII, normal building inspection should not be assumed to replace the required rater verification.
The required compliance documentation must be completed through the applicable Energy Code process.
Does the Energy Consultant Perform the QII Inspection?
Preparing the Title 24 calculations and performing the required third-party field verification are separate functions unless a specific service arrangement expressly provides otherwise.
AES can identify QII in the energy documentation and help coordinate the calculation with the construction plans. Required field verification is completed separately by an appropriately qualified rater.
Are Residential Additions Required to Use QII?
The 700-Square-Foot Threshold Is Important Under Prescriptive Compliance
For single-family additions, project size matters.
Under the 2025 prescriptive requirements, additions greater than 700 square feet are subject to QII.
An addition of 700 square feet or less has a prescriptive exception from that QII requirement.
This distinction is particularly important for:
- Room additions
- Second-story additions
- Attached ADUs
- Expanded conditioned living areas
Does an Addition of Exactly 700 Square Feet Require Prescriptive QII?
The current prescriptive language applies QII to additions greater than 700 square feet.
An addition at or below that threshold can qualify for the applicable prescriptive exception, subject to the remaining Energy Code requirements.
Can a Smaller Addition Still Have QII?
Yes.
The prescriptive exception does not prevent QII from being used as a performance-compliance measure.
If QII is modeled for compliance credit, the applicable air barrier and insulation installation still need the required third-party field verification.
Does the 700-Square-Foot Exception Mean Insulation Quality Does Not Matter?
No.
An exception from formal prescriptive QII verification does not eliminate applicable mandatory insulation requirements, manufacturer installation requirements, or other building-envelope provisions.
It means the project is not automatically subject to the specific prescriptive QII verification requirement solely because of the addition under that size threshold.
What About an Attached ADU?
An attached ADU constructed as an addition can be affected by the same project-scope and area rules.
The California Energy Commission specifically confirms that the prescriptive QII requirements do not apply to ADU additions of 700 square feet or less.
However, when QII is modeled for performance credit, an ECC Rater must verify the applicable air barrier and insulation installation.
What About a Detached ADU?
A newly constructed detached ADU is generally treated as a newly constructed residential building for applicable Energy Code requirements rather than merely as an addition to the existing house.
Its Title 24 documentation should therefore be reviewed as a new residential project.
For project-specific guidance, review ADU Title 24.
What About a Garage Conversion?
A garage conversion can involve newly conditioned space rather than a traditional building addition.
The correct treatment depends on how the project is classified under the Energy Code and what compliance method is used.
The project should be reviewed before assuming that the 700-square-foot addition exception automatically applies to every garage conversion.
Can Performance Compliance Avoid the Prescriptive QII Requirement?
QII Can Be Traded Off, but the Energy Model Accounts for the Difference
This is one of the most important distinctions when determining Is QII Required in California.
The California Energy Commission states that QII is not a mandatory requirement in the same sense as a mandatory measure that cannot be traded away.
When a single-family project uses the performance compliance method, QII can be traded off with other efficiency measures.
However, that does not mean the software simply ignores QII.
What Happens in the Energy Model if QII Is Not Used?
The 2025 compliance modeling rules assume verified QII in the standard design for applicable new single-family buildings and additions greater than 700 square feet.
If the proposed design does not pursue QII, the compliance software reduces the modeled effectiveness of applicable insulation.
The project then needs enough performance elsewhere to remain within the permitted energy budget.
Why Is There an Energy Penalty Without QII?
The modeling adjustment reflects the fact that ordinary field installation can contain construction defects that reduce thermal-envelope performance.
Potential problems include:
- Insulation gaps
- Voids
- Compression
- Open framing pathways
- Incomplete air barriers
Verified QII allows the model to take credit for higher-quality installation.
Can Other Measures Offset Not Using QII?
Potentially.
Under the performance method, the project may be able to use other qualifying efficiency improvements to offset the modeled impact of not using verified QII.
Possible project characteristics can include:
- Higher-performing windows
- Improved insulation assemblies
- More efficient HVAC equipment
- Improved roof assemblies
- Other qualifying energy measures
The specific tradeoff must be demonstrated through CEC-approved compliance software.
Can I Decide During Construction to Skip QII?
Do not make that decision solely in the field.
If the approved Certificate of Compliance assumes QII, eliminating the measure can change the performance calculation.
The energy consultant should review the project and determine whether a revised compliant design is available.
Can QII Be Removed After the Framing Inspection Was Missed?
Potentially, but only through appropriate compliance review.
If a required QII inspection was missed, the project should not simply delete the measure from the paperwork and continue.
A revised energy analysis may be needed, and other measures may need to compensate for the loss of QII credit.
Is Performance Compliance Always Easier Than QII Verification?
Not necessarily.
The better approach depends on:
- Building design
- Envelope performance
- Equipment efficiency
- Construction schedule
- Available tradeoffs
- Cost of alternate efficiency measures
Sometimes keeping QII can be more practical than redesigning other portions of the project.
Does QII Apply to Multifamily Buildings?
Low-Rise Multifamily Requirements Include an Important Climate Zone 7 Exception
QII also appears in California’s multifamily Energy Code requirements, but the rules should not be copied directly from single-family projects without checking the building classification.
Under the current 2025 multifamily requirements, buildings up to three habitable stories have prescriptive QII requirements in Climate Zones 1 through 6 and 8 through 16.
Climate Zone 7 is an important exception for applicable low-rise multifamily QII requirements.
Why Is Climate Zone 7 Different for Low-Rise Multifamily?
California’s multifamily prescriptive requirements do not impose the same QII requirement in Climate Zone 7 that applies in the other listed climate zones.
This exception is specific to the applicable multifamily provisions and should not be confused with the single-family prescriptive rules.
Who Verifies Multifamily QII?
For applicable low-rise multifamily QII projects, an ECC Rater performs the required third-party field verification.
Current California multifamily compliance forms include separate QII documentation for:
- Air-infiltration sealing at the framing stage
- Insulation installation
Do Multifamily Additions Have QII Requirements?
California’s residential field-verification reference materials summarize QII as a prescriptive measure for applicable newly constructed buildings and additions greater than 700 square feet, subject to the low-rise multifamily Climate Zone 7 exception.
The actual building type, story count, climate zone, addition size, and selected compliance method should be confirmed before scheduling verification.
Does QII Apply to High-Rise Multifamily the Same Way?
No assumption should be made that every multifamily building uses the same residential QII procedure.
QII provisions specifically distinguish building categories and applicable low-rise multifamily conditions.
The project should be evaluated under the correct multifamily requirements.
Does QII Apply to Commercial Buildings?
The residential QII process should not automatically be applied to nonresidential construction.
Commercial and nonresidential buildings have their own envelope requirements, installation provisions, acceptance procedures, and documentation.
If a project contains residential and nonresidential occupancies, the applicable compliance requirements should be coordinated according to the actual building classification.
Why Building Classification Matters
The words “residential building” are not enough to determine the complete QII requirement.
The project may need to distinguish among:
- Single-family residential
- Low-rise multifamily
- Other multifamily construction
- Mixed-use construction
- Nonresidential occupancy
AES can review the project documents and determine which compliance provisions apply.
When QII Is Required, Construction Scheduling Becomes Critical
Framing and Insulation Must Remain Accessible for Verification
QII is different from many paperwork-only compliance requirements because it depends on construction-stage verification.
The current California single-family forms include separate documentation for:
- QII air-infiltration sealing at the framing stage
- QII insulation installation
This means the project team needs to know about the requirement before drywall or other finishes conceal the relevant work.
When Should the ECC Rater Be Contacted?
Ideally, before the applicable construction work is concealed.
Scheduling should allow the rater to verify required conditions during the appropriate stages.
That can involve coordination among:
- General contractor
- Framing contractor
- Insulation contractor
- Energy consultant
- ECC Rater
- Project owner
What Happens at the Framing Stage?
The framing-stage portion addresses applicable air-infiltration sealing and air-barrier conditions.
The work must remain sufficiently visible for the applicable verification procedure.
What Happens at the Insulation Stage?
The rater can verify applicable insulation conditions such as:
- Installed insulation type
- Insulation levels
- Gaps
- Voids
- Compression
- Installation around obstructions
- Hard-to-access cavities
- Attic conditions
- Other project-specific envelope details
What if Drywall Is Installed Before QII Verification?
That can create a significant compliance problem because the required conditions may no longer be visible.
The project team should contact the rater and energy consultant before assuming photographs or other documentation will automatically substitute for the required field verification.
Can Photographs Replace the Inspection?
Do not assume so.
QII verification must follow the applicable California procedures administered through the ECC Program.
The rater and applicable program requirements determine what verification is acceptable.
What if the Insulation Fails QII Verification?
The contractor normally needs to correct the identified condition so the applicable verification criteria can be satisfied.
Potential deficiencies can include:
- Missing insulation
- Gaps
- Voids
- Improper compression
- Incomplete air barriers
- Incorrect insulation levels
- Installation that does not match the approved energy documentation
The goal is to correct the work while it remains accessible.
Does a Failed QII Inspection Mean the Permit Is Permanently Lost?
No.
A failed verification item means the applicable deficiency needs to be resolved.
The project should correct the work and complete the required compliance process.
Current California Projects Use the ECC Program
Older Projects May Still Show HERS Terminology
The 2025 Energy Code changed the terminology used for Energy Code field verification and diagnostic testing.
The California Energy Commission’s Energy Code Compliance Program replaces the field-verification portion of the former HERS Program for Energy Code compliance.
Current terminology includes:
- ECC Program
- ECC Provider
- ECC Rater
- Field Verification and Diagnostic Testing
Older documents can still contain:
- HERS Provider
- HERS Rater
- HERS verification
When Did the ECC Change Take Effect?
The change took effect with the 2025 Energy Code on January 1, 2026.
The applicable Energy Code version is generally tied to the permit application date.
What if My Project Uses the 2022 Energy Code?
Projects governed by an earlier Energy Code can continue using the compliance terminology and forms associated with that code cycle.
A 2022-code project may therefore continue to display HERS terminology even though current 2025-code documentation uses ECC terminology.
Should Old QII Documents Be Converted to New Forms?
Not simply because the calendar year changed.
First determine which Energy Code version governs the permit.
For additional guidance, review Which Title 24 Energy Code Version Do I Need.
What Documents Show Whether QII Is Required?
The project’s Certificate of Compliance is one of the most important documents to review.
It identifies applicable field-verification measures associated with the compliance design.
Current 2025 single-family QII forms include:
- CF2R-ENV-21-H QII Air Infiltration Sealing – Framing Stage
- CF2R-ENV-22-H QII Insulation Installation
- CF3R-ENV-21-H QII Air Infiltration Sealing – Framing Stage
- CF3R-ENV-22-H QII Insulation Installation
The California Energy Commission publishes these forms as part of the current 2025 single-family Energy Code compliance documents.
What Is the Difference Between CF2R and CF3R?
In the current single-family documentation system, CF2R forms document applicable installation information while CF3R forms document required verification.
Both can be part of demonstrating that a QII measure was properly installed and verified.
Does the Title 24 Report Replace the QII Verification Forms?
No.
The energy report identifies the energy-compliance design.
Required field-verification documentation establishes that applicable measures were installed and verified during construction.
They serve related but different purposes.
Find Out Whether Your California Project Requires QII
Call (626) 365-1518 | Alternative Energy Systems
The safest way to answer Is QII Required in California for a specific project is to review the actual Title 24 documentation.
Useful information can include:
- Current construction plans
- Project type
- Addition square footage when applicable
- Energy Code version
- Certificate of Compliance
- Title 24 calculations
- Insulation specifications
- Existing HERS or ECC documents
- Building-department correction notices
What if QII Is Already Listed on My Report?
Do not ignore the requirement.
The project team should determine which verification stages apply and schedule them before the relevant construction is concealed.
What if I Do Not Want QII?
Ask for a compliance review before construction proceeds.
Depending on the project, the performance approach may allow the design to demonstrate compliance without QII, but the software will account for reduced insulation effectiveness and other efficiency measures may be needed.
Can AES Determine Whether QII Can Be Removed?
AES can review the energy analysis and determine whether an alternate compliant design can be prepared.
That does not guarantee QII can be removed from every project.
The available options depend on:
- Project design
- Envelope performance
- HVAC efficiency
- Windows
- Roof design
- Other available efficiency measures
What if the Building Department Asks About QII?
Send AES the complete correction notice together with the current plans and energy documentation.
The issue may involve:
- Missing forms
- Missing field verification
- Plan notes
- Insulation specifications
- A mismatch between the plans and energy report
- An outdated code-cycle form
Why Choose Alternative Energy Systems?
Alternative Energy Systems provides professional Title 24 calculations, energy-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 projects
- Envelope compliance
- Projects involving QII
- Energy-related plan-check corrections
AES prepares the energy-analysis side of the project and can identify required field-verification measures. Third-party verification remains a separate rater function unless the project agreement specifically states otherwise.
Learn more through the About Us page, review company background on the clients page, or explore Title 24 energy compliance.
Frequently Asked Questions: Is QII Required in California?
Is QII Required in California?
QII is a prescriptive requirement for many residential projects, including newly constructed single-family buildings and additions greater than 700 square feet under the 2025 prescriptive path. It is not universally required for every California permit.
Is QII required for every new single-family home?
Under the 2025 single-family prescriptive compliance path, QII is required for newly constructed buildings in all California climate zones.
Is QII a mandatory measure that can never be traded off?
No. The California Energy Commission states that QII is not a mandatory measure under the performance approach. It can be traded off with other efficiency measures.
What happens if a performance project does not use QII?
The compliance software reduces the modeled effectiveness of applicable insulation in the proposed design, so the project needs sufficient energy performance elsewhere to comply.
Is QII required for an addition over 700 square feet?
Under the applicable single-family prescriptive provisions, QII applies to additions greater than 700 square feet.
Is QII required for an addition of 700 square feet or less?
There is an applicable prescriptive exception for additions at or below 700 square feet. QII can still be used for performance credit, in which case verification is required.
Is QII required for an ADU addition under 700 square feet?
The California Energy Commission confirms that the prescriptive QII requirement does not apply to an ADU addition of 700 square feet or less. If QII is modeled for performance credit, verification is still required.
Is QII required for a detached ADU?
A newly constructed detached ADU is generally treated as new residential construction for applicable Energy Code requirements. Its compliance documents should be reviewed to confirm the required measures.
Is QII required for a garage conversion?
Not automatically. The answer depends on how the conversion is classified under the Energy Code and which compliance method is used.
Is QII required for a remodel?
Not every remodel requires formal QII verification. The project scope, code provisions, and compliance method determine whether QII applies.
Is QII required in every California climate zone?
For newly constructed single-family buildings under the prescriptive path, QII applies in all climate zones. Low-rise multifamily has a Climate Zone 7 exception under the applicable current provisions.
Is QII required for low-rise multifamily buildings?
Current prescriptive requirements apply QII to applicable multifamily buildings up to three habitable stories in Climate Zones 1 through 6 and 8 through 16. Climate Zone 7 is excluded from that prescriptive requirement.
Is QII required for commercial buildings?
The residential QII verification process should not automatically be applied to nonresidential projects. Commercial buildings have separate envelope and compliance requirements.
Who verifies QII?
For current 2025 Energy Code projects, an appropriately qualified ECC Rater performs required third-party field verification.
Is a HERS Rater still used?
Current 2025-code documentation uses ECC terminology. Earlier code-cycle documents can continue to use HERS terminology.
When did California change to ECC?
The Energy Code Compliance Program replaced the Energy Code field-verification portion of HERS with the 2025 Energy Code effective January 1, 2026.
Does QII require more than one inspection?
Applicable QII documentation includes framing-stage air-sealing verification and insulation-stage verification.
Can QII be inspected after drywall?
Required QII conditions should be verified while they remain accessible. Concealing the work before verification can create compliance problems.
What if QII fails?
The applicable installation deficiency should be corrected so the required verification can be completed.
Can QII be removed from the Title 24 report?
Potentially under a compliant revised performance design, but removing it can affect the energy model and may require other efficiency improvements.
Can photographs replace an ECC Rater inspection?
Do not assume they can. Required verification must follow the applicable California procedures and ECC Program requirements.
Does QII guarantee permit approval?
No. QII is one part of Energy Code compliance, and the complete project remains subject to all other applicable permit requirements.
How do I know whether my project has QII?
Review the project’s Certificate of Compliance and Title 24 energy report for listed field-verification measures.
What should I send AES?
Send the current plans, Certificate of Compliance, Title 24 calculations, insulation specifications, code-cycle information, existing HERS or ECC documents, and any building-department corrections.
How do I get help determining whether QII applies?
Call Alternative Energy Systems at (626) 365-1518, email info@title24energy.com, or use the contact page.
When service and payment have already been arranged, payment can be completed through the AES payment page.
