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Development Services

From Concept to Construction

Phone: 503-823-7300

TTY : 503-823-6868

1900 SW 4th Ave, Portland, OR 97201

Enlarging the Building Footprint

Applying For My Permit

The following information must be submitted when applying for this kind of permit. Since every project is unique, there may be some situations where you will be asked to provide additional information.

To submit for a permit, bring the above materials along with intake fees to the Development Services Center.

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 ofOregonand carry a current CCB license.

THINGS TO CONSIDER

(1) Included work, such as an Attached Garage or Additional Floor

If your project will include the addition of a garage, please also see our page on Garage, Shed and Accessory Structures for special requirements.

Additional requirements may apply if the scope of work includes converting existing unfinished space to living space, or adding a dormer or additional floor to the house. Please refer to the summary page for more information.

(2) Residential Engineering

Your project must be designed to meet all structural requirements in the building code. The construction drawings must show how both gravity and lateral (wind and earthquake) loads will be resisted.  Please see our page on Residential Engineering for more information on these requirements.

(3) Floodplains

If your house is located in a floodplain, there are restrictions that may limit your ability to add to or significantly improve your house without retrofitting it to be flood-resistant. Please contact Site Development staff at (503) 823-6892 to discuss your project.

(4) Decommissioning a Septic Tank or Cesspool

When enlarging the footprint of an existing structure, septic tank/cesspools must be located and shown on the site plan.

  • Visit the records staff at the Development Services Center to research plumbing records showing septic systems/cesspools
  • If the septic system/cesspool has been decommissioned, and is within 10 feet of the new structure, you must sign a disclaimer for on-site-sewage disposal system form
  • If the septic system/cesspool is within 10 feet of the new structure and has not been pumped and filled, it will need to be decommissioned

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