ADU Permitting Process

A building permit cover sheet.

Step-by-Step Guidance to Get Your Project Approved

Step 1: Set Up Your Permit Account

If you plan to manage the permitting process yourself, go to MyBuildingPermit.com and create an account. You'll use this portal to submit plans, track progress, and schedule inspections. Otherwise, some architects or contractors offer services to navigate the permitting process outlined below for you.

Step 2: Prepare Your Submittal

Using a Pre-Approved DADU Plan? You’ll need to submit:

  • Site Plan (must include plan Registration ID)
  • Supplemental Building Information Form
  • ADU Registration Application
  • Plumbing Worksheet
  • Survey (in most cases)
  • Geotechnical Report (if applicable)
  • Rodent Abatement Letter (if required)
  • Fire Sprinkler Permit (if required)
  • Demolition Permit (if removing structures)

Not using a pre-approved DADU Plan?  No problem – just visit our Development Services webpage for more information on the submittal requirements for standard ADU permitting.

Step 3: Know If Your Property Needs Extra Review

Projects near lakes, streams, slopes, or wetlands may need further review and permitting. Check with the Planning Department at 425-587-3600 if you're unsure.

Step 4: Qualify for Expedited Review

To fast-track your review, please be sure to review the full requirements of an expedited review. 

Step 5: Build Your ADU

Once your permit is approved:

Step 6: Final Inspection & Move-In

After passing the final inspection:

  • Receive your certificate of occupancy
  • If renting, obtain a business license
  • Follow landlord and rental rules

For more detailed information regarding using a pre-approved DADU design and the submittal requirements, please read this document.(PDF, 227KB)

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