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Construction Permit - Addition or Alteration

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What Is It?

You need a construction permit to remodel or add onto your building, whether it is a single-family house, multifamily building, or a commercial or industrial building. New structures that are accessory to an existing house, such as a backyard cottage, are considered additions.

  • An addition involves changes to the outside of the building, such as adding floor area
  • A remodel (also known as an alteration) is when you make changes to the building’s interior, like moving non-structural walls

Examples of common projects are adding a second floor, creating another living unit in your home, or remodeling a building for a new business.

How Much Does It Cost?

Fees are based on the value of your project. You pay approximately 75 percent of your fee when you submit your plans and the rest when you pick up your permit. Use our fee estimator to estimate how much your permit will cost. We will also charge hourly fees for certain reviews, such as drainage and geotechnical; see our Fee Subtitle for details.

How Long Does It Take?

We try to finish our initial review of simple permit applications in 2-3 weeks and complex permits in 8 weeks.

How long it takes to get the final permit depends on how complex your project is and how many corrections, if any, you need to make.

If you have a small project, you may be able to get a same-day permit called a subject-to-field-inspection permit.

Steps to Get Your Permit


1. Research

Get your property information. Find property information to help you plan your project.

Determine restrictions to your project. Research our codes to determine building size limits and construction and life / safety requirements.

Find incentives for your project. Research the City's different incentives that might apply to your project.

Determine if you need a land use permit. If your project is not a single-family building, you might need a Land Use / Master Use Permit. We need 4 to 8 months (or more) to review land use permits, which must be submitted before you submit your construction permit application.

Attend a coaching session. We offer 20 minutes of free coaching at the Applicant Services Center to answer drainage, land use, geotechnical or construction permit questions. If you need a longer coaching session, we offer one-hour sessions for a fee.

2. Start Permit Application

Apply for a project number. Get a project number by starting your preliminary application online through your Project Portal. You will need to upload a site plan and a complete legal description for your site.

Request a pre-application site visit. You need a pre-application site visit if you will disturb more than 750 square feet of land or disturb any land on a site with an environmentally critical area (other than liquefaction or peat-settlement prone areas). Request a pre-application site visit online through your Project Portal. You'll receive an email once we have added the pre-application site visit (PASV) fees to your project. After you have paid the fee, we will perform the inspection. Your preliminary application materials will be sent to other departments for their review and comment as part of this process. You will receive a preliminary application report that will include critical information about whether you need Design Review, SEPA, or street improvements. Our report will include information from the utilities about your specific site and proposal. Our report will also identify potential project stoppers.

Note: If your project requires street improvements, Seattle Department of Transportation (SDOT) may require you to submit plans to them at least 5 days before your permit intake appointment. We will not accept your project at intake if you haven't submitted these plans.

Request a pre-submittal conference (optional). We recommend pre-submittal conferences for very complex projects, including buildings with unusual structural systems, substantial alterations, or work in environmentally critical areas or shorelines. One-hour pre-submittal conference fees vary based on the type of conference you need.

Apply for exemptions. You may need an exemption if your project is located in an environmentally critical area or near the shoreline.

Prepare your plans. Plans should be to scale and easy to read and scan.

Fill out forms.

Coordinate with other agencies. You may need permits or approvals from other agencies. These are the most common agencies you may need to work with for your permit type:

3. Submit Plans

Get your project screened. We screen your application to make sure it is ready to submit. Screening is available on a walk-in basis at the Applicant Services Center or through your Seattle DCI Project Portal.

Schedule an intake appointment. Schedule an electronic intake appointment through your Project Portal. You may schedule an appointment without screening if you are a consistently prepared applicant with a rating of 80 percent or better.

Pay fees. Approximately 75 percent of your permit fees are due at intake. The fees are calculated based on your project value.

Make corrections and resubmit your plans. Once all of our reviews are done, you will receive an email telling you that corrected and/or additional documents can be uploaded into your portal. Your project may require multiple correction rounds before our reviews are complete.

4. Get Permit

Pay final fees. We will notify you if you need to pay any final fees before we issue your permit.

Print your permit. We will notify you when we have issued your permit and the documents are available in your Seattle DCI Project Portal. Print the permit and approved plan set and have it on site for our inspector.

Get related permits. You may need to get additional permits or approvals from other departments.

5. Schedule Inspection

Request an inspection. See the construction inspections page for when to call us and how to schedule your inspection.

6. Complete Project

Receive your certificate of occupancy. You only need a certificate of occupancy if you have changed the use of, or number of residences in, your building. Single-family and duplex projects never need a certificate of occupancy; you just need a final "approved" inspection for your project.

Close your permit. Your permit information will be archived in our electronic document management system.

What Do You Want To Do?

Still Need Help?

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  • Call us at (206) 684-8850