Applying for a detached accessory dwelling unit using a pre-approved standard plan is an expedited review and permitting process. To be eligible for this expeditated process, your project must:
- Use a pre-approved standard plan for a detached accessory dwelling unit project located only in a neighborhood residential (NR-1, NR-2, or NR-3) zones (no other zone is eligible).
- Not have any environmentally critical areas on the project property.
- Have less than 750 square feet of total ground disturbance (which includes the structure and driveways).
For more information about plans that are pre-approved, please see the ADUniverse pre-approved DADU gallery.
- Log in to your Seattle Services Portal account or create one.
- Click on Permits – Trade, Construction, & Land Use link under Create New.
- Expand Building Permits, click the Building & Land Use Pre-application.
- Enter your address and click Search.
- Verify or select your address and then click Continue.
- Identify an Applicant and Owner and then click Continue.
- Complete the Application Details fields.
- Select Yes when asked if you are making additions or changes to an existing building.
- Select Yes when asked if you plan to use an existing approved standard plan set.
- Provide a valid Standard Plan #.
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Select Yes when asked if you think your project qualifies as a subject-to-field-inspection or a Detached Accessory Dwelling Unit (DADU) standard plan.
Do not answer "Yes" to any other question in the Application Details section. If you answer "Yes" to any question in this section that is not specifically noted above, including "I'm constructing a new building," your application will likely end up requiring unnecessary preliminary steps that will delay your project.
- Select Yes when asked if you are making additions or changes to an existing building.
- Click Continue.
- Complete the rest of the required Application Details fields and click Continue.
- Select No when asked if you are disturbing ground in an environmentally critical area.
- Select No when asked if you will have new and replaced hard surface greater than 750 square feet.
- Select No when asked if you are doing more than 2,000 square feet of earth disturbance.
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Select Add/Alt as the Action Type in the Building Code Information section.
Selecting anything other than "Add/Alt" will likely cause your project to require unnecessary preliminary steps that will delay your project.
- Upload the following documents:
- Site plan with a legal description and parcel number.
- Statement of Financial Responsibility form (if required – see Director's Rule 5-2003).
- Rat Abatement Declaration form (required if removing an accessory structure such as a garage or shed).
- King County sewer treatment capacity charge form.
- Plan set that includes a site plan showing the existing buildings on the site, the proposed DADU, including a pedestrian path from the right-of-way to the DADU, and the approved standard plans for the DADU.
- Click Continue.
- Review your information, make necessary edits, and then click Continue to submit your application.
- You will be contacted with the next steps to get your permit once we have processed the application.