Manufactured Home Residential Building Permits

Get information, required forms, and helpful handouts for residential building permits for manufactured homes in the City of Portland. Learn about the mobile home permit review process and inspections and factory-built home permits and modular home permits.

You need a building permit to install a manufactured home

You need a building permit to install a manufactured home or mobile home. 

There are three different permit types for manufactured dwellings:

  1. Manufactured Dwellings on an Individual Lot (MI)
  2. Manufactured Dwellings in Parks (MP)
  3. Residential (RS) for accessory structures (these structures must be constructed per the International One and Two Family Dwelling Code)

Manufactured homes include modular homes, factory built homes and permanent mobile homes (mobile homes without wheels, on a foundation).

Who can do the work

Contractors must have a license to work in Oregon. The Oregon Construction Contractors Board (CCB) issues licenses to contractors. The permit application and their company materials must list the license number. Need help finding a contractor? The CCB website has good tips on how to search for one. Plumbing and Electrical contractors have additional license requirements.  

If you are a homeowner doing the work yourself, then you can sign the trade permit applications. You cannot do the electrical work yourself. You must hire a licensed electrical contractor to do the electrical work. The State of Oregon has some helpful information for homeowners: 

Building permit application and other important forms

The following information is part of the application. This is everything you might need when applying for a manufactured home permit. Since every project is unique, there may be some situations where you will be asked to provide additional information. 

Things you need to apply for this permit may include some or all of the following. Read more about site plans and other items to include in your application

If you aren't sure what you need, contact the Permitting General Information phone number. You also might want to read our step-by-step guide for completing a building permit application. Permit forms and information include: 

Step 1: Research your property and what you need for your project

When you need manufactured home permits

A building permit is required when installing a manufactured home. Depending on the scope of work, your project may also require electrical, plumbing or mechanical permits

Any accessory structures, site-built additions or alterations to existing homes will be reviewed under provisions in the Oregon Residential Specialty Code. 

How to check the permit history for a house 

Depending on the age of the home, we may have information about the permit history. It is important to verify the permit records, and not rely on the tax information from the county assessor’s office. 

Some records are available online, visit the How to Request Public Property Records webpage.

Code and Rules

Manufactured dwelling installation is governed by the Oregon Manufactured Dwelling Standard (OMDS) and City Title 24.90. The State of Oregon reviews and inspects the construction of manufactured structures. The City of Portland reviews and inspects the structural support of the structure, and any site-built elements such as stairs, decks, patio covers and garages.

  • Oregon Residential Specialty Code 
  • Portland City Codes 
    • Title 11 Tree Code 
    • Title 24 Building Regulations
    • Title 33 Zoning Code 

Other codes may apply based on the scope of work. The City and State Codes, Administrative Rules, Code Guides and Program Guides web page has the codes, administrative rules, code guides and program guides.

Planning and Zoning

Before getting started, contact a city planner to find out if a manufactured home is allowed on your property. Schedule a free 15-minute appointment or call the General Inquiries phone number at 503-823-7300.

Alterations to manufactured homes 

Alterations to manufactured dwellings require a permit and plans. The State issues the permit if the alteration is before the time of sale to the first consumer. The City issues the permit if it is a “secondary alteration” after the initial sale to the first consumer. Any alteration or addition that adds vertical weight or lateral loads to a manufactured dwelling requires engineering, including adding interior masonry around a wood stove or cutting a header.

Appliances in mobile homes 

Appliances such as electric ranges and clothes dryers must be listed for use in manufactured dwellings. Solid fuel-burning appliances, such as fireplaces, wood stoves, and pellet stoves must be listed for use in manufactured dwellings.

Gas and oil fuel-burning appliances, such as furnaces and water heaters, do not need to be listed for use in manufactured dwellings. These appliances can be installed according to their listing.

When you need a building permit and trade permits (combination permits)

The Bureau of Development Services sells a "Residential Combination" permit package. This allows you to call for all inspections using one Building Permit (RS) IVR number. You can also pay for all the permits at one time. If you choose a combination permit, you will need to submit the trade (mechanical, electrical, and/or plumbing) applications with your plans.  If you are hiring subcontractors to do the trade work, they must sign their trade permit application.  

Contractors must have a license to work in Oregon. The Oregon Construction Contractors Board (CCB) issues licenses to contractors. The permit application and their company materials must list the license number. Need help finding a contractor? The CCB website has good tips on how to search for one.  Plumbing and Electrical contractors have additional license requirements.  
Oregon Construction Contractors Board 

Decommissioning a septic tank or cesspool

If the home is placed on a site that was previously developed, you will need to research if there is a septic tank or cesspool. If the prior home was not connected to the sewer when it was built, you will likely need to decommission the cesspool or septic tank.  

Permit fees

Permit fees are based on the type of permit, the work proposed, the valuation of the work, and the staff that need to review the work. Read more about permit fees


A Ramada is a structure built over the home but not attached to the home. It must be a minimum of 18 inches above the top of, and six inches beyond the sides of, a manufactured dwelling. A ramada is reviewed and permitted like a pole structure, and requires an engineered design.

Site modifications for basements, carports, decks, driveways, garages, and more

  • All site modifications such as driveways, daylight basements, ramadas, cabanas, carports, garages, additions, porches, decks, etc. must be shown.
  • Except for porches and decks, any accessory structure must be permitted separately.
  • A home that has a roof overbuild must be shown as adequate to support such overbuilding. A home that has trusses designed to support 30 psf snow load will be assumed capable of supporting a simple garage gable extension.

Step 2: What you need for a manufactured home permit

The following information must be submitted when applying for a permit to install a manufactured dwelling. Since every project is unique, there may be some situations where you will be asked to provide additional information. Please include:

  • The floor plan from the manufacturer 
  • NSFR New Single Family Residence Application packet
  • If lot slope exceeds 20%, submit a geotechnical engineering report prepared by an engineer registered in the State of Oregon

Site Plan (Scale site plans to minimum scale of 1”=10’ and at least 11” x 17” in size)

  • Lot and building setback dimensions.
    • The “lot” for a manufactured dwelling on an individual lot (MI) is the property line
    • The lot for a manufactured dwelling installed in a park (MT) would be the lot within the park where the home is located.
  • Property corner elevations (if there is more than a four foot elevation differential, the site plan must also show existing and proposed contour lines at two foot intervals. A separate grading plan may be required to legibly show grading changes.)
  • Location and dimensions of easements and driveways
  • Footprint of structure (including decks and dimensions of eaves)
  • Location of wells/septic systems
  • Lot area
  • Location of all cuts and fills on the lot
  • Building coverage area and percentage of coverage
  • North arrow
  • Impervious area (structures, paving, etc.)
  • Existing structures on site
  • Location of utilities (storm & sanitary sewers, water, gas, etc. including size of service and street location)
  • Surface drainage
  • Width of adjacent right-of-way and curb height
  • Landscape plans
  • For a manufactured dwelling installed in a park, a plan of the park detailing the separate lots with the lot identified where the specific manufactured dwelling will be installed
  • A manufactured dwelling that is installed within a floodplain must meet elevation requirements

Building Elevations drawn to scale and showing:

  • All four views (left, right, front, and rear) of manufactured home, including foundation
  • Finished grade for specific site
  • Exterior siding material
  • Roof pitch (3/12 minimum) and eave overhang (12” minimum)
  • The City also requires that sections show that the home is a maximum 12” above grade at the lowest point, has conventional residential siding and at least 12” eaves

Foundation Plan (drawn to ¼” =1’ scale )

  • Concrete runners, slab and pads
  • Spacing for supports (piers, blocks, etc)
  • Size of all components
  • Section detail
  • Pier locations either per OMDS or manufacturer’s specifications
  • 18 x 24 crawl access
  • Ventilation
  • Skirting or perimeter walls. Perimeter walls up to four feet high, measured from the bottom of the footing to the top of the wall, structural CMU, grouted solid or solid concrete, or pressure-treated wood pony walls shimmed 16” center to center are acceptable ( 304n, OMDS). The OMDS states that all perimeter walls must be engineered.
  • Poly will be laid in the crawl space and subsurface disposal will be required at the direction of the inspector
  • Tie down locations with manufacturer’s listing information or structural engineer stamp for single-wide homes

Note: Daylight basements require plans and calculations stamped by an Oregon Registered Structural Engineer. 

Perimeter Wall Section Detail (Skirting)

  • Framing details
  • Footing details
  • Attachment details

Step 2b: Still need help? Schedule a 15-minute appointment 

This is an optional step. If you still need help, we are here for you if you have questions about the information and materials you need to apply. You can schedule a free 15-minute appointment with any of these reviewers:

  • Meet with a City Planner to receive information about planning and Zoning and Tree Code requirements that apply to your property. 
  • Meet with a Building Code and Engineering Reviewer to get help with building code and engineering requirements. 
  • Meet with a Permit Technician if you have questions about the permit process or if you need help with application requirements.

If you need help, these are experts we recommend you meet with for this project. Not all review groups are listed. The groups listed above will help get you started. 

Step 3: Apply for a manufactured home permit

You can submit your permit application request online using Development Hub PDX.

If you need to submit paper plans, you can set up an appointment to pick up plans or drop off plans in person. Or, please call us and we will work with you. 

Step 4: Check plan review status and make corrections to an application

After you pay intake fees, your project will be "under review." You can check the status of a permit review on Portland Maps permit/case search. Many people might review a single permit. The Permit Review Process web page has more information about the groups that review permits. 

A checksheet is sent to the applicant when a reviewer needs additional information or a correction has to be made to the plans. Read more about how to send us corrections and how to prepare corrected paper plans.

Step 5: Get your manufactured home permit 

We'll contact you when your permit is ready, and notify you of any fees due. We'll give you instructions on how to get your approved permit and pay your fees. Your permit is not issued until all fees are paid. Read more about the pre-issuance process.

Step 6: Start installation and get ready for inspections

The inspection card lists all the inspections you will likely need during your construction project, and what work needs to be done first.  

Once your building permit is issued, erosion control measures and sometimes tree protection measures must be installed, inspected, and approved prior to beginning any further ground-disturbing activities.

All permits need a final approval inspection to be complete.

Step 7: Schedule an inspection, get inspection results and make corrections

To schedule an inspection, call the automated Requests for Inspections phone number. You will need your IVR or permit number and the three-digit code for the inspection.

Get the results of the inspection on Portland Maps permit/case search the next day.

Read more about why work does not get approved and how to schedule a reinspection.

Contact residential inspectors about your permit inspections

If you have questions before or after your inspection, you can talk to an inspector.

More information about residential permits

Read more about residential permit projects: