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.
There are three different permit types for manufactured dwellings:
- MI (Manufactured Dwellings on an Individual Lot)
- MP (Manufactured Dwellings in Parks)
- RS (Residential) 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).
Manufactured home permit application and important forms
Step 1: Research your property and what you need for your project
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. Building Codes, Rules & Guides has links to the codes and administrative rules, code and program guides.
Planning and Zoning
Before getting started, contact Planning and Zoning to find out if a manufactured home is allowed on your property.
Important information about 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.
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 such as electric ranges and clothes dryers must be specifically listed for use in manufactured dwellings. Solid fuel burning appliances, such as fireplaces, wood stoves and pellet stoves must be specifically listed for use in manufactured dwellings.
Gas and oil fuel-burning appliances, such as furnaces and water heaters, do not need to be specifically listed for use in manufactured dwellings. These appliances can be installed as per their listing.
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.
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.
- 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 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
- 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 3: How to submit your manufactured home permit application
Schedule a Building Permit Intake Appointment.
Smaller projects are submitted through the Single PDF process.
If you are unable to create electronic plans yourself, please call us and we will work with you.
You'll receive an email confirming your appointment time. You'll need to upload your completed permit application and all submittal materials before the appointment. A secure link will be provided in the email confirmation.
Step 4: Manufactured home plan review process and checksheets
After you pay intake fees, your project will be "under review". The bureaus/review groups that will check a typical manufactured dwelling installation project are:
- Planning and Zoning
- Life Safety Review
- Structural Review
- Site Development Review
- Residential Subsurface Site Evaluation - Site Development
- Bureau of Environmental Services Review
- Portland Bureau of Transportation Review
- Water Bureau Review
- Urban Forestry Review
A checksheet is sent to the applicant when a reviewer needs additional information or a correction has to be made to the plans. When you have gathered the additional information or made the corrections, bring the plans/information to the Development Services Center. Reviewers will be notified that a checksheet response has been received and the review will continue.
The permit review process webpage has more information. You can check the status of the permit review on Portland Maps permit/case search.
Step 5: Permit issuance
When the last technical review is approved, your permit will be pre-issued. Pre-issuance is the last permit check. This step ensures all required reviews took place, all required approval stamps are on the plans, and the fees are charged correctly. You will be contacted when your permit is ready, and notified of your final fee total. Instructions will be given on how to get your approved permit and pay your fees. Your permit is not issued until all fees are paid.
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: Residential inspections, results and corrections
To schedule an inspection, call the automated inspection request line. 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.
Not approved - there are some reasons why the work did not get approved:
- no access - the inspector may not have been able to inspect the work
- incomplete work
- code violations
The inspector will list the corrections needed on the inspection report.
Call for a reinspection after making the corrections. Use the same three digit inspection code.
If you make the corrections the same day wait until 5 pm to request a reinspection. The inspector needs to enter their results before you can schedule the reinspection.
There is a reinspection fee charged for more than one reinspection for a single issue.
Contact residential inspectors
If you have questions before your inspection, you can talk to an inspector. The 1 & 2 family inspector area map list the inspector's name, area, and phone number.
Because of vacation or illness, your inspector may be different than the one listed on the map. If you have questions after your inspection, find out which inspector to call. Their contact information will be on the inspection results and on Portland maps.