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
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)
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.