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Cargo Shipping Containers

Building Permit Requirements


Cargo containers, also known as intermodal freight containers, are standardized, reusable portable vessels that were originally designed for use in intercontinental traffic of freight and designed to be mounted on a rail car, truck or ship. When such containers are used as a building or structure, they are subject to the provisions of the building code as adopted and modified by King County. Accordingly, a building permit is required to locate and use such structures. The site and building construction plans shall be adequate to demonstrate compliance with building, fire and site regulatory standards. Structural calculations are required for altered or structurally connected containers.


As with other prefabricated structures such as portables or manufactured homes, building code approval of cargo containers may be obtained through the Washington State’s Factory Built Structure Agency.



  1. Residential accessory storage structures less than 200 SF
  2. A container used for storage of construction materials and equipment associated with a valid building or grading permit for the property on which it is located.


Exempt structures as noted above shall be:

  1. Not located in required setbacks, parking spaces or fire lane
  2. Separated by at least 10’ from all other buildings
  3. Comply with all other building and site requirements as determined appropriate
  4. Non-heated, not used as a habitable space


Code References:

•           2015 Internal Building Code Sect. 105.1- Permit Required

•           King County Code Sect. 16.02.240  - Work Exempt from Permit

Clearing refers to the cutting or removal of vegetation or other organic material by any means.

Questions on permit requirements for clearing are posed in a number of different ways. For example:

  • Do I need a permit to cut down one tree? What about 7 trees?
  • Do I need a permit to remove a tree that has fallen into a creek?
  • Do I need a permit to remove some blackberries?
  • Do I need a permit to top a tree?
  • I don't want to remove any trees but I would like to remove all of the vegetation from around the trees.
  • I want to remove a tree that is dying that I am concerned may come down in a windstorm. Do I need a permit?

Clearing regulations for unincorporated King County are rather complicated in that they vary according to geographic area. As a general rule, a clearing permit is required for any removal of trees or vegetation from a critical area or from properties subject to urban clearing standards or clearing restrictions in a special district overlay defined in 21A.38) of the King County Code. Clearing an accumulative 7,000 square feet on RA zoned properties or removal of 5,000 board feet of merchantable timber also requires a permit. A separate Forest Practice Permit may also be required. There are some exceptions:

  • Normal and routine maintenance of lawns and landscaping.
  • Permitted agricultural and horticultural uses.
  • Emergency tree removal.
  • Removal of noxious weeds from steep slopes, buffers of streams and wetlands.
  • Hand removal of blackberries from aquatic area buffers with an approved rural stewardship plan.

Permits also are required if an individual is conducting a Class IV forest practice. This involves harvesting of 5,000 or more board feet timber.

Please also refer to the Permitting Department Customer Information Bulletin #28, Clearing and Grading Permits. For more information about clearing restrictions and permitting requirements in your area, call the Permitting Department customer service at 206-296-6600.

If illegal clearing involves logging over 5,000 board feet, property in unincorporated King County would be subject to a six-year development moratorium, in addition to any other remedies allowed by code. This could include obtaining an after-the-fact permit, restoring the property to a condition that meets whatever development conditions apply to the property, and payment of double permit fees and possibly civil penalties.

In unincorporated King County, a building permit is required to construct a deck or walking surface more than 30 inches above the ground. All structures more than 18 inches above the ground must comply with zoning regulations and setbacks and be built according to the Uniform Residential Code.

A 36-inch high guardrail with maximum openings such that a 4-inch sphere can not pass through is required to be installed for any walking surface that is more than 30 inches above the adjacent ground surface.

Application materials are available online at in the Residential - Addition/Remodel Decks, Garages, Sheds Packet or by contacting the Permitting Department at 206-296-6600. Deck Tip Sheet

For decks that have not been properly permitted, the Permitting Department can review the structure and issue an Already Built Construction (ABC) permit. If the deck is not consistent with King County Code, applicants would be required to bring the structure into compliance. A field visit is required and ABC permits are typically issued within 1-2 months.

More information can be found using the Density and Dimension charts (PDF*, 204KB) in Chapter 21A.12 of the King County Code (KCC) at

In unincorporated King County, fences can be constructed six feet tall or less without the need to obtain a building permit. The fences can be located up to the property line except at street intersections or access points.

At intersections (street corners) and access points (driveways), a site distance triangle must be maintained for traffic safety reasons. The two sides of the triangle from the intersection point shall be 15 feet in length. Within the triangle, fences can be no higher then 42 inches. Reference 21A.12.210 (PDF*, 204KB) of the King County Code.

Fences also can be located on top of retaining walls. The total height of the wall and fence cannot exceed ten feet with the fence portion not exceeding six feet in height.  See KCC 21A.14.220 (PDF*, 134KB).

Electric fences are allowed in all zones, however, in most urban residential zones, additional fencing or other barriers can be constructed to prevent inadvertent contact from abutting property. Other requirements must also be met. See KCC 21A.14.220C (PDF*, 134KB) for more information.

Barbed or razor fencing is not allowed in most urban residential zones (R-4 through R-48).

Grading refers to any excavating, filling, removing of the duff layer, or combination thereof. "Excavation" is the removal of earth material. "Fill" is a deposit of earth material placed by mechanical means. "Duff layer" is the partly decayed organic layer on the forest floor.

Questions as to the requirement for a grading permit can be posed in a number of different ways. For example:

  • I want to put in a 40-foot long driveway. Do I need a permit? What about for a 400-foot driveway?
  • Do I need a permit to replace a water line to my house?
  • I have an existing landscape berm in front of my house that is three feet high. Do I need a permit to increase its height to five feet?
  • I want to excavate 75 yards of gravel from the front of my lot to construct an RV storage area at the back of my lot. Do I need a permit?
  • What is the maximum number of cubic yards of dirt that can be removed, or brought in, before a permit is required?
  • Do I need a permit to fill in my swimming pool?
  • Is a grading permit required to bring in 125 cubic yards of topsoil to redo my yard?

Grading regulations for unincorporated King County can be complicated. As a general rule, any grading within a sensitive area, or any excavation greater than five feet in depth or over 100 cubic yards, or any fill greater than three feet in depth or greater than 100 cubic yards, or creation of more than 2,000 square feet of new impervious surface, requires a permit. There are some exceptions:

  • An excavation or fill for a basement footing etc., for a structure authorized by a valid building permit or that has been approved in conjunction with review of a plat or commercial site development permit (note: as long as the work is covered by the building permit).
  • Maintenance of existing driveways or private access roads. Changing the surfacing of an existing road, say, from gravel to asphalt or native surface to gravel, is not considered a maintenance activity and would be subject to the same thresholds mentioned above.
  • Any grading within a publicly owned road right-of-way.

In trying to determine if a permit is needed or not, there are several things to keep in mind:

  • Grading exemption thresholds are not annual limits, but are cumulative and relate to the overall project.
  • Permit thresholds do not recognize property lines.
  • Even when a grading permit is not required, other permits (such as a clearing permit) still may be required.

Please also refer to the Permitting Department Customer Information Bulletin #28, Clearing and Grading Permits (PDF*, 157KB). For more information about clearing restrictions and permitting requirements in your area, call the Permitting Department customer service at 206-296-6600.

In unincorporated King County, basic roof repairs or reroofing of existing buildings typically does not require a permit.

A permit is required if a heavier roof covering, such as a tile roof, replaces an existing composition or wood shingle or shake roof. If the roof structure, such as trusses or rafters, is altered or replaced, a permit is required. For commercial structures, the fire resistive rating of the roof must not be diminished.

For more information on exemptions from building permits, reference section 16.02.240 (PDF*, 398KB) of the King County Code.

Under the 2015 International Residential Code, in unincorporated King County, you may build a detached residential storage shed with a floor area of 200 square feet or less without a permit. In addition, you must meet all zoning code requirements including setbacks, clearing limits, and lot coverage.