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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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Major Residential Alteration and Addition Permit – Overview and Criteria


The following information on the Major Residential Alteration and Addition (Portland City Code Section 24.55.210) permit outlines what a Major Residential Alteration and Addition permit is and what notification and delay requirements apply. There is also information on definitions and links to the Major Residential Alteration and Addition Notification Form that must be submitted prior to permit issuance.

What is a Major Residential Alteration or Addition?

Major alteration or addition is defined as any of the following: 

    1. Adding any new story, including a basement or other below-grade structure. Raising a structure to meet the required headroom in a basement is considered the same as creating a basement;
    2. Increasing or replacing 50 percent or more of the exterior wall area on any floor. If the subflooring under an exterior wall is removed, it will be treated as if the wall was removed;
    3. Adding total new floor area to the existing structure that exceeds 800 square feet; or
    4. Adding an area exceeding 100 percent of the existing foundation footprint area of the structure.

Where Do the Notification and Delay Regulations Apply?

The Major Residential Alteration and Addition delay applies to sites with residential structures in areas with a residential Comprehensive Plan Map designation.

The regulations only apply to applications for major alterations and additions of residential structures. They do not apply to accessory structures such as garages or other outbuildings.

Delay Requirements

The building permit for a major residential alteration or addition will not be issued until 35 days have passed from the time that the required notice has been sent by the property owner/owner’s representative as described below. The owner/owner’s representative may complete this notice prior to applying for a building permit in an effort to coordinate the permit issuance with expiration of the required 35 day delay period. All notification requirements must be met for the 35 day delay timeline to commence. 

Notification Requirements

If a residential project falls within the criteria above, notice is required to be sent by the property owner applying for the permit or the owner’s representative as follows:

  1. Emailed notice: At least 35 days before a building permit is issued for a major residential alteration or addition, the applicant for the permit must email a letter (View sample letter) to the recognized organization(s) whose boundaries include the site (View Map) that contains at least the following information:
    • Notice that an application for a major alteration or addition has been or will be submitted to the Bureau of Development Services;
    • The date the application was filed, if applicable;
    • A general description of the proposed alteration or addition;
    • Notice that there is a delay period of 35 days from the date the notice is sent; and
    • The contact information of the applicant.

  2. Posted notice: At least 35 days before the building permit is issued, the applicant must post door hangers provided by BDS on the properties abutting or across the street from the site of the project. The notice must contain all of the following information.   
      • Notice that an application for a major alteration or addition has been or will be submitted to the Bureau of Development Services;
      • The permit application number, if an application has already been filed;
      • The approximate date the construction activity will commence;
      • Contact information of the agencies that regulate asbestos and lead-based paint; and
      • Contact information for the applicant.  Site Notice

BDS has created a Major Alteration and Addition Neighborhood Notice Certification form to comply with these requirements.

Certification Regarding Asbestos and Lead-Based Paint 

All applicants for Major Residential Alterations and Additions (Portland City Code Section 24.55.210 must complete a Certification Regarding Asbestos and Lead-Based Paint certifying that they have had the area of disturbance tested and if the area contains asbestos or lead-based paint, the area will be remediated prior to work commencing.


Subflooring. Subflooring means the bottom-most structural floor laid as a base for a finished floor.

Recognized organization. Recognized organization includes neighborhood coalitions and neighborhood associations recognized by the Portland Office of Neighborhood Involvement.