Arizona Is Preparing for a Major Manufactured Housing Code Update
The Arizona Office of Manufactured Housing has announced plans to update the building codes used for the projects it regulates. The Office anticipates that the new codes will take effect on December 5, 2026. The update includes several 2024 International Codes and the 2023 National Electrical Code.
According to the announcement, all plans will require an update. Designers, manufacturers, installers and applicants planning projects for late 2026 or beyond should begin reviewing their plans and coordinating with the appropriate design professionals.
The Office currently lists the 2018 ICC codes and 2017 NEC as its adopted editions. Additional guidance is expected regarding the transition and how it will affect plans that are submitted, under review or already approved.
Key Takeaways
The anticipated effective date is December 5, 2026.
The update includes several 2024 International Codes and the 2023 National Electrical Code.
The change applies to projects regulated by the Arizona Office of Manufactured Housing, not every construction project in Arizona.
The announcement says plans will require updates, so applicants should begin coordinating with their design professionals.
Final transition rules for submitted, pending and approved plans have not yet been published.
Which Building Codes Is Arizona Adopting?
The Arizona Office of Manufactured Housing currently lists the 2018 ICC codes and 2017 NEC as its adopted editions. The announced transition would move most covered codes to the 2024 editions and the electrical code to the 2023 edition.
| Building Code | Currently Listed | Announced Edition |
|---|---|---|
| International Building Code (IBC) | 2018 IBC | 2024 IBC |
| International Residential Code (IRC) | 2018 IRC | 2024 IRC |
| International Mechanical Code (IMC) | 2018 IMC | 2024 IMC |
| International Plumbing Code (IPC) | 2018 IPC | 2024 IPC |
| International Fuel Gas Code (IFGC) | 2018 IFGC | 2024 IFGC |
| International Energy Conservation Code (IECC) | 2018 IECC | 2024 IECC |
| National Electrical Code (NEC) | 2017 NEC | 2023 NEC |
| International Fire Code (IFC) | Not currently listed | Selected 2024 provisions |
December 5, 2026 is the anticipated effective date. Final implementation guidance is still expected from the state.
The announced Arizona Office of Manufactured Housing update covers building, residential, mechanical, plumbing, fuel gas, energy, electrical and fire code requirements.
Most of the International Codes currently listed by ADOH are from 2018 and are expected to move to the 2024 editions. The National Electrical Code would move from the 2017 edition to the 2023 edition. The announcement also includes selected portions of the 2024 International Fire Code.
Additional IRC and IFC Provisions
The announced 2024 International Residential Code adoption specifically includes Appendix BB for Tiny Houses and Appendix BC for Accessory Dwelling Units.
The selected portions of the 2024 International Fire Code include:
Chapters 1 through 3
Chapters 6 through 12
Chapters 20, 23 and 24
Chapters 31 through 33
Appendices B and F
This Update Is Specific to the Office of Manufactured Housing
This announcement applies to projects regulated by the Arizona Office of Manufactured Housing. It does not mean that every city, town or county in Arizona will change its building codes on the same date. Local jurisdictions may use different code editions and amendments, so applicants should confirm every agency involved in reviewing their project.
When Will the New Arizona Manufactured Housing Codes Take Effect?
The Arizona Office of Manufactured Housing anticipates that the new codes will take effect on December 5, 2026. However, this remains an anticipated date while the state completes the adoption process and prepares additional guidance.
The announcement does not yet explain how the transition will affect plans submitted, under review or approved near the effective date. It also does not establish a final submission deadline for using the currently adopted codes.
Applicants should not assume that submitting before December 5 will automatically allow a project to remain under the older codes. They also should not assume that previously approved plans must be resubmitted without first confirming their status with the Office of Manufactured Housing.
Transition rules are still being developed: Confirm the applicable code edition and plan requirements with the Office of Manufactured Housing before making decisions based solely on the anticipated date.
Who Should Prepare for the Arizona Code Change?
The upcoming code transition may affect anyone involved in designing, manufacturing, reviewing, installing or permitting a project regulated by the Arizona Office of Manufactured Housing.
This may include:
Factory-built and modular building manufacturers
Licensed dealers and installers
Architects and engineers preparing plans or calculations
Third-party inspection agencies
Contractors performing regulated installation work
Developers using factory-built construction
Property owners submitting covered plans
Homeowners planning attached accessory structures
Applicants requiring floodplain installation plans
Companies relying on standard or repeat plan sets in Arizona
The exact effect will depend on the building type, scope of work, plan status and reviewing authority. Applicants should confirm whether their project falls under the Office of Manufactured Housing and whether additional state or local approvals will be required.
Which Arizona Plan Review Submittals Could Be Affected?
The ADOH Plan Review page identifies several categories of plans and supporting documents reviewed by the Office of Manufactured Housing. The upcoming code transition may affect each type of submittal differently, depending on its scope, status and applicable code requirements.
Factory-Built Building Plans
Residential and commercial factory-built building submittals generally include plans and calculations prepared for a licensed manufacturer. These documents cover buildings manufactured off-site and must be approved before construction and certification can proceed.
Manufacturers should review active design packages for outdated code references, calculations, specifications and construction details.
Installation Plans
Factory-built building installation submittals may include:
A site plan
Foundation plans and calculations
Utility information
Site-specific installation details
Plans for attached accessory structures
These documents should be reviewed together so that the building, foundation, utilities and site installation details reference the correct code editions.
Accessory Structure Plans
ADOH reviews plans and calculations for certain structures attached to manufactured homes, mobile homes or factory-built buildings. Examples may include garages, carports, patios, porches, decks, storage rooms, habitable additions, retaining walls, solar systems and skirting.
The code update may affect the plans, calculations and connection details used for these structures.
Floodplain Plans
Projects in designated flood-prone areas may require a site-specific foundation plan prepared by a licensed design professional. The proposed foundation system must also receive approval from the local flood authority before it is submitted to ADOH.
Applicants should confirm that the engineering calculations, local approval and ADOH documents are based on the correct code requirements.
Reconstruction Plans
Reconstruction review may apply to existing factory-built buildings brought into Arizona or previously approved buildings undergoing reconstruction. Plans must identify the extent of the new construction and any changes to electrical, plumbing, mechanical or other building systems.
New work may need to comply with the codes in effect at the time of reconstruction, making the timing of the transition especially important.
Standard and Repeat Plans
Manufacturers using standard or repeat plans should inventory every plan set intended for future Arizona projects. Cover sheets, code references, calculations, specifications and standard details may need to be revised before the plans can be used under the new codes.
Not every submittal will be affected in the same way. Applicants should confirm the applicable requirements with ADOH and their design professionals before updating or resubmitting documents.
Does the Code Change Apply to HUD-Code Manufactured Homes?
Not necessarily. Manufactured homes and factory-built buildings may both be constructed off-site, but they follow different regulatory paths.
HUD-Code Manufactured Homes
HUD-code manufactured homes are designed and constructed under the federal Manufactured Home Construction and Safety Standards. These federal standards govern the home’s construction, design and major systems, including plumbing, electrical and fire safety.
Factory-Built Buildings
Factory-built buildings are constructed under the building codes, standards and procedures adopted by the Arizona Department of Housing. ADOH specifically states that its factory-built building plan category does not include manufactured homes built to HUD standards.
Where State and Local Requirements May Still Apply
Even when a manufactured home is constructed under the federal HUD Code, state or local requirements may still apply to:
Installation
Foundation systems
Floodplain work
Attached accessory structures
Reconstruction
Utilities and site work
Local zoning and land use approvals
The building type, project scope and reviewing authority must be identified before determining which codes and plan review procedures apply.
The announcement should not be interpreted to mean that every HUD-code manufactured home must be redesigned under the 2024 IRC.
Why Existing Arizona Plans May Require Revisions
The state’s announcement says that plans will require an update. Because several code editions are changing at the same time, updating a plan may involve more than replacing the code year on the cover sheet.
Practical Plan Review List
Depending on the project, a design professional may need to review:
Code references on cover sheets
General construction notes
Structural calculations
Foundation designs
Energy compliance documentation
Mechanical layouts and equipment
Plumbing systems
Fuel gas systems
Electrical plans
Fire and life-safety details
Material specifications
Testing and inspection notes
Standard details used across multiple plan sets
This is a practical review list, not an official ADOH checklist. The documents requiring revisions will depend on the project type, scope and applicable code provisions.
Updating the code edition on the cover sheet alone may not be enough. Plans, calculations, specifications and supporting documents should be reviewed together to confirm that they are consistent with the applicable code edition.
What the 2024 IRC Could Mean for Arizona Tiny Homes and ADUs
The announced code update specifically includes two 2024 International Residential Code appendices addressing tiny houses and accessory dwelling units. Their inclusion gives Arizona applicants clearer building-code provisions to consider, but it does not automatically determine where these projects are allowed.
2024 IRC Appendix BB for Tiny Houses
Appendix BB applies to dwelling units with 400 square feet or less of floor area, excluding lofts. It includes provisions designed for compact homes, including requirements related to lofts, ceiling heights, stairs and ladders.
Its inclusion in the announcement makes tiny houses an important part of the upcoming code transition. However, the project must still follow the requirements of the reviewing agencies and the property’s local jurisdiction.
2024 IRC Appendix BC for Accessory Dwelling Units
Appendix BC provides design and construction provisions for accessory dwelling units. Depending on the project and local regulations, an ADU may be detached, attached to a primary residence or created by converting existing space.
Compliance with Appendix BC does not automatically establish that an ADU is permitted on a particular property. Local requirements may still address:
Zoning and permitted land uses
Property setbacks
Building height and lot coverage
Parking and access
Water and utility connections
Septic or wastewater capacity
Fire and emergency access
Site development standards
The inclusion of Appendices BB and BC does not automatically legalize tiny homes or ADUs throughout Arizona. Local zoning, site requirements and other approvals still apply.
How to Prepare Before the Expected December 2026 Code Change
Applicants do not need to wait for the final transition rules to begin preparing. Organizing plans, confirming responsibilities and identifying possible revisions now can help reduce last-minute problems later.
1. Inventory Your Arizona Plans
Identify every active, standard, repeat and project-specific plan that may be submitted or used after December 5, 2026. Include plans still in development and previously approved plans intended for future projects.
2. Record the Status of Every Plan
Sort plans based on their current status:
Still in design
Ready for submission
Submitted and awaiting intake
Under review
Approved but not yet used
Previously approved as a standard plan
This will help the project team identify which plans may require immediate attention once the state publishes its transition instructions.
3. Confirm the Reviewing Authority
Determine whether the project requires review from the Arizona Office of Manufactured Housing, a local jurisdiction or both. The reviewing authority will determine which code editions, applications and approval procedures apply.
4. Coordinate With the Design Professional
Ask the project’s architect or engineer to identify drawings, calculations, specifications and details that may be affected by the newer codes. Starting this review early gives the design team more time to prepare coordinated revisions.
5. Review the Complete Submittal Package
Do not review the drawings in isolation. Applications, checklists, engineering calculations, product information, specifications and supporting documents may also need to be updated.
6. Monitor Official Updates
Watch the ADOH website and Plan Review page for final adoption documents, transition instructions, revised forms and updated checklists. Requirements may change as the anticipated effective date approaches.
7. Avoid Incomplete Early Submissions
ADOH requires a completed plan review application and the applicable checklist with submitted plans and documents. Rushing an incomplete package into the review process may create additional comments, correction requests or delays.
8. Allow Time for Plan Review
ADOH states that expedited plan review is not available and applications are reviewed in the order received. Project schedules should allow time for intake, review, design revisions and resubmittals.
What If Your Plans Are Already Submitted or Approved?
ADOH has not yet published complete instructions for plans at different stages of the review process. Applicants should evaluate each plan individually and confirm the applicable requirements before revising, submitting or resubmitting documents.
Plans Still in Design
The design team should consider the expected code transition before completing the package. Plans intended for submission or use after December 5, 2026 may need to reflect the newer code editions.
Plans Ready but Not Submitted
Confirm which code edition ADOH expects based on the planned submission and review schedule. Do not assume that submitting before December 5 will automatically allow the plan to remain under the older codes.
Plans Currently Under Review
Ask whether the existing review will continue under the codes used for the original submittal or whether updated documents will be required. Avoid making unnecessary revisions until the applicable requirements have been confirmed.
Plans Already Approved
Confirm whether the approval will remain valid after the transition. Applicants should also ask whether later revisions, renewals or repeat use of an approved plan will trigger review under the newer codes.
Important: These scenarios describe questions applicants should ask, not confirmed transition rules. Final requirements will depend on the policy published by the Arizona Office of Manufactured Housing.
ADOH Approval May Be Only One Part of the Permit Process
An ADOH plan approval addresses the portion of the project reviewed by the Arizona Office of Manufactured Housing. It does not necessarily replace local approvals for the property, site development or installation.
Depending on the project and location, additional review may involve:
Local planning and zoning departments
City or county building departments
Fire departments or fire districts
Flood control districts
Environmental health departments
Utility providers
Septic or wastewater authorities
Grading and drainage reviewers
Site development permit authorities
The agencies involved are determined by the property address, building classification and scope of work. For example, an ADOH-approved factory-built building may still require local zoning clearance, utility approval, grading review or a site development permit before installation can proceed.
The order and requirements for these approvals can vary by jurisdiction. Identifying every reviewing agency early helps prevent a project from reaching one approval stage while still missing a separate local requirement.
Permit Pushers helps applicants identify the permit path, organize jurisdiction requirements and coordinate submittals across the agencies involved.
Could the Code Change Affect Arizona Plan Review Times?
Code transitions can sometimes increase submission activity as manufacturers update standard plans and applicants work toward an anticipated effective date. However, ADOH has not confirmed that this transition will create a backlog or specific review delays.
ADOH currently states that expedited plan review is not available and that applications are reviewed in the order received. The total timeline can also be affected by:
Incomplete applications or missing documents
Plan review comments
Design revisions
Delayed responses from the project team
Additional agency approvals
Required resubmittals
Applicants should allow time for design coordination, document preparation, initial review and possible corrections. Rushing an incomplete submission to meet the anticipated transition date may create more delays than submitting a complete, coordinated package.
Preparing an Arizona Project for Plan Review
The upcoming ADOH code transition adds another layer of coordination for Arizona projects. Applicants may need to confirm the reviewing authorities, update submission documents and keep several project partners working from the same requirements.
Permit Pushers manages the administrative side of the permit process. Our team can help:
Identify the likely state and local reviewing agencies
Confirm current applications, checklists and submission requirements
Organize plans and supporting documents
Coordinate documents with architects, engineers and project teams
Submit permit packages
Monitor plan review status
Track comments and requested corrections
Coordinate revised documents and resubmittals
Communicate with reviewing agencies
Keep project records and approvals organized
Permit Pushers does not provide engineering, plan design or formal code interpretation. Those services must be completed by the appropriate licensed design professionals. We help keep the documents, communication and permit process organized while the project team handles the technical work.
Have an Arizona project planned for late 2026 or 2027? Start reviewing the permit path now.
Start Preparing Before the Code Transition
The Arizona Office of Manufactured Housing anticipates that several new code editions will take effect on December 5, 2026. With the 2024 International Codes and 2023 National Electrical Code changing at the same time, projects planned for late 2026 or 2027 may require early preparation.
Applicants should coordinate with their design professionals, confirm whether ADOH or a local jurisdiction will review the project and verify which code edition applies. Reviewing the entire submittal package is also important. Incomplete documents, outdated code references and uncoordinated revisions can lead to avoidable plan review comments.
Permit Pushers helps applicants organize requirements, coordinate documents, communicate with reviewing agencies and manage the permit process from submission through approval.
Arizona Manufactured Housing Code Update FAQs
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The Arizona Office of Manufactured Housing has announced an anticipated effective date of December 5, 2026. The date and transition procedures should be confirmed through final guidance from the Office.
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The announcement includes the 2024 IBC, IRC, IMC, IPC, IFGC and IECC, selected portions of the 2024 IFC and the 2023 NEC. The 2024 IRC adoption also includes Appendix BB for Tiny Houses and Appendix BC for Accessory Dwelling Units.
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No. The Arizona Office of Manufactured Housing currently lists the 2018 ICC codes and 2017 NEC as its adopted editions. The newer editions are expected to take effect in December 2026.
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The announcement states that plans will require updates. However, ADOH has not yet published complete instructions explaining how the transition will apply to plans that are already submitted, under review or approved.
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No. HUD-code manufactured homes are constructed under the federal Manufactured Home Construction and Safety Standards. State or local requirements may still apply to installation, foundations, additions, attached accessory structures, reconstruction and other site-related work.
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A manufactured home is constructed under federal HUD standards. An Arizona factory-built building is a residential or commercial building manufactured off-site and constructed under the codes, standards and procedures adopted by the Arizona Department of Housing.
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No. Appendix BB provides building-code provisions for qualifying tiny houses, but it does not determine where they are allowed. Local zoning, land use, utility and site requirements still apply.
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No. Appendix BC provides design and construction provisions for accessory dwelling units. Local zoning and development regulations still determine whether an ADU is allowed on a particular property.
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ADOH has not yet published complete transition instructions for pending plans. Applicants should confirm the applicable code edition with the Office before revising or resubmitting documents.
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No. The Office currently states that expedited plan review is unavailable and that applications are reviewed in the order received.
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Email: adohplanreview@azhousing.gov
Plan Review phone: 602-771-1099Verify current contact information on the official ADOH Plan Review page before reaching out.
Published August 17, 2026
Last updated August 17, 2026