Do I Need a Permit?

When is a permit required?
Snohomish County regulates the construction of many different types of buildings. Most structures require the applicant to submit a building permit application and site development plan. Residential building permits can be divided into four basic categories:
  • Single Family Residential (RK)
  • Manufactured Homes (MH)
  • Accessory Buildings (AB)
  • Other residential permits
When is a permit not required?
Common examples are non-habitable structures under 400 square feet in rural zones and non-habitable structures under 200 square feet in urban zones and uncovered decks constructed 30 inches or less from ground level.
Please refer to assistance Bulletin # 74 for other projects that are exempt from building permit requirements. Please keep in mind that exempt structures may not require building permits but they must still comply with distances from property lines as well as environmental regulations.
If your project is listed below and you wish to start the process click here to START

You can also apply for many of our permits online at For additional information about please see our Online Permitting page.

The links below are provided for more information because some projects have additional requirements.
Single Family Residential (RK)

Garage with Living Space
Guest House
Attached Accessory Apartment
Detached Accessory Apartment
Interior Remodel
Manufactured Homes (MH)

Mobile Home
Mobile Home in Mobile Home Park
Modular Home
Temporary Dwelling
Residential Accessory and Non Accessory Buildings (AB)

Agricultural Building
Aircraft Hanger
Boat House
Covered Porch
Garage/Storage Building
Retaining Wall
Swimming Pool

You may be eligible for a tax exemption on your improvements. Click here for more information.
Other Residential Permits
Inspection Report
Pre-Application Conference
Lot Status
Land Disturbing Activity Permit 
Flood Hazard
Shoreline Permits
Shoreline Exemption

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