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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

Getting Started

Any project that enlarges the footprint of an existing building requires a building permit. Enclosing a porch or adding new living space to your house are examples of projects that require a building permit. Depending on the scope of work, electrical, plumbing or mechanical permits may also be required.

Your permit will be reviewed for compliance with the Portland Zoning Code, the Building Code and other local regulations.  

  • Applicable Cityand State Codes:  Refer to the Codes page on the Bureau of Development Services (BDS) website.
  • Portland’s applicable building code is the Oregon Residential Specialty Code. See the  State Codes page for more information about this and other construction codes in effect.
  • The Portland Zoning Code, (City Title 33) includes use regulations and development standards, such as maximum building footprint coverage and setbacks, and can be found on the Zoning Code page.

General Information

Our "New Users"  tab is a good place to start for overall information about the permitting process.

Researching Building Permit Records for Your House

Before preparing building permit plans, it is important to verify that existing finished space in your house was legally permitted. The BDS maintains building permit records that can help you prepare plans for your current house project. Historical inspection cards or microfilmed permit plans may be available to determine the existing “permitted” condition of your house.  Although the Multnomah County Assessor maintains information about your house’s living area (available on PortlandMaps.com), this information may not match the building permit history. There is no "grandfathering-in" of unpermitted finished or living areas, and to be considered legal living area, a permit is required.

Permit Fees

Permit fees are based on the fair market value of the work included in the permit.