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The City of Portland, Oregon

Development Services

From Concept to Construction

Phone: 503-823-7300


1900 SW 4th Ave, Portland, OR 97201

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Manufactured Homes

Information related to manufactured homes: putting one in a new location or altering an existing home.

Getting Started

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. 

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)

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. View more information on building codes. 

It is recommended to visit or call the Planning and Zoning staff (503) 823-7526 and Buildings staff (503) 823-7310 at the Development Services Center early in the planning of your project.

Applying For My 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.

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

Include the Floor Plan from Manufacturer

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

To submit for a MP permit, bring the completed building permit application and four (4) copies of site, floor, elevation, foundation, perimeter wall section, related materials and intake fees to the Development Services Center.

To submit for an MI permit, contact the Permitting Services staff at (503) 823-4172 to schedule a new single family residential (NSFR) intake appointment.

Information on the addition of an accessory building.

Information on the addition of a deck.

If you are hiring sub-contractors to do work on your project, and know who they are when applying, they will be listed on your permit at that time. If you don't know when you apply for your permit, they can be added after issuance. Sub-contractors you hire must be registered with the State of Oregon and carry a current CCB license.


(1) Appliances

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.

(2) Ramadas

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.

(3) Alterations

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.

(4) Site Modifications

  • 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.

(5) Decommissioning a Septic Tank or Cesspool

When installing a manufactured dwelling on an individual lot, the septic tank/cesspool must be located if it exists.

  • Visit the records staff at the Development Services Center to locate any old plumbing records showing a septic system/cesspool
  • If the septic system/cesspool is decommissioned, and within ten feet of the new structure, you must sign a disclaimer for on-site-sewage disposal system form
  • If the septic system/cesspool is within ten feet of the new structure, it will need to be decommissioned

Call Environmental Soils staff at (503) 823-6892 for more information on decommissioning septic tanks and cesspools.

Plan Review Process

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 Review
  • Life Safety Review
  • Structural Review
  • Addressing
  • Site Development Review
  • Bureau Of Environmental Services Review
  • Plumbing Review (if five or more fixtures are altered or installed)
  • Portland Department of Transportation Review
  • Urban Forestry Review

Overview of the permitting process

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.

More information on checksheets

Status Reports
Status reports are available after your project has been assigned to reviewers. Status reports show all reviews and include the reviewer’s name and phone number. To obtain a status report, call (503) 823-7000 and select option four (4) to have a status report faxed to you or call (503) 823-7357 to have one mailed to you. 

Permit Issued
When the last technical review is approved, your permit will pre-issued. You will be contacted when your permit is ready, and of your final fee total. Fees may be paid by cash, check, Visa or Mastercard. 

If your permit is ready for issuance, you may pick up your permit between 8:00 am - 3:00 pm, Monday-Friday at Permitting Services, located on the 2nd floor of 1900 SW 4th Avenue, Portland, OR. For more information call (503) 823-7357. 


The yellow 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 must be installed, prior to beginning any further ground disturbing activities.

Applications & Handouts