Decks & Fences
Before making any repairs, additions or modifications to a deck that is more than 30 inches above grade (measured to the lowest point within 6 feet of the deck), you need a permit. Note: Removing, altering or repairing railings or guards is considered a modification.
If you are only replacing / repairing non-structural decking boards, you are exempt.
Be aware that even if no permit is required, any modified decks or patios must still meet current land-use regulations. These include, but are not limited to, the maximum impervious surfaces allowed on your lot. Please contact the Permit Center if you are unsure.
Single-Family Deck Permit Submittal Requirements
Submit your application on MyBuildingPermit.com. At the end of the application you will be asked to upload a plan set. It must include the site plan and deck plans together in one PDF. See the Tip sheets section for assistance with details.
If the size of the deck is changing, the following is required:
- Front, rear and side yard setbacks
- Property area
- All structure dimensions / sizes (for impervious surface calculations)
- Impervious surface calculations
- Title block - include property owner information, site address and page number
Deck plans must include the following:
- Fully dimensioned floor plan, 1/4-inch/foot scale
- Framing plan and details (fully-dimensioned framing plan showing spacing and span of posts, handrails and size of pier footings)
- Stair details
- Handrail details
- Guardrail details
- Foundation details
You may include MyBuildingPermit.com Tip Sheets instead of creating your own. On that page you may find the following sheets to be helpful:
- Number 5 Basic Deck Tip sheet
- Number 1 Basic Stairs Tip sheet
- Number 2 Guards Tip sheet
- Number 3 Handrails Tip sheet
- The maximum height in the front setback is 4 feet.
- The maximum height in the side and rear setbacks is 6 feet.
- Additional HOA restrictions or approvals may be required.
- For more information, see IMC 18.600.090.
Residential fences do not require a building permit unless the fence is:
- In a critical area
- More than 6 feet in height
- Other land-use restrictions exist
Determining Your Property Line
In newer-platted areas you may find buried corner markers — look for a piece of rebar in the ground. The Permit Center or King County may have plat maps to assist you in finding your property lines and/or dimensions. Please be aware that ultimately it is up to the property owner to verify property line locations, which may require a professional survey.