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Those of you living in rural areas often inquire about requirements for constructing agricultural buildings. Below is a brief introduction to the permitting process and permit application requirements for agriculture buildings in unincorporated King County.

What is the definition of an "agricultural building"?

They are structures designed for farming and agricultural practices, including but not limited to: growing and harvesting crops and raising livestock and small animals. Examples include:

  • barns
  • greenhouses
  • storage buildings for farm equipment, animal supplies or feed
  • storage buildings for equipment used to implement farming and/or agricultural practices
  • storage buildings for crops grown and raised on site (cold storage)
  • horticultural nursery.

A building permit is required for an agricultural building.

We issue building permits and enforce building standards unique to agricultural buildings; for example,

  • design standards for wind and roof loads,
  • allowable area and fire code provisions.
  • If the proposed use exceeds that of an ag building (e.g., public riding arenas, sales areas, etc.), more stringent standards may be applied.

Permit fees are reduced for agricultural buildings required by commercial farming operations located on properties that are:

  • Enrolled in current use taxation; or
  • Located in the Agricultural Production District and enrolled in the Farmlands Preservation Program; or
  • Located in the Agricultural Production District and having an approved farm plan prepared by the King Conservation District;
  • Located in the RA zone, having an approved farm plan prepared by the King Conservation District, and having a valid state business license as a commercial farming operation.
  • For additional detail, please contact us at 206-296-6600.

What are the application requirements for an agricultural building?

Our Bulletin #9, Obtaining a Residential Building Permit*, describes the submittal requirements for a building permit. If you anticipate your use of the agricultural building to include the public or employees, then see the submittal requirements outlined in Bulletin #8, Commercial and Multifamily Building Permits*.

In what zoning classifications are agricultural uses allowed?

Agricultural uses are allowed in most of the rural areas of unincorporated King County. This includes properties zoned Ag (A) & Rural Area (RA).

  • For agricultural product sales, the permitted use table is found in 21A.08.070* of the King County Code (KCC).
  • For growing and harvesting crops and raising livestock and small animals, see KCC 21A.08.090*.
  • For stables (as defined in KCC 21A.06.1220*), see KCC 21A.08.050*.

Some of the conditions for these practices may include: limitations on the size and sales and/or storage areas and hours of operation; requirements for annual sales projections from products grown or produced in King County; limitations on signs and lighting.

What are the required setbacks from property lines?

For complete details, see KCC 21A.12.122* Setbacks - Livestock buildings and manure storage areas. Some general guidelines are noted below:

  • The minimum setback from interior property lines for any building used to house, confine or feed swine shall be 90 feet.
  • The minimum setback from interior property lines for any building used to house, confine or feed any other livestock shall be 25 feet.
  • The minimum setback from interior property lines for any manure storage area shall be 35 feet.
  • The typical street setback is 30 feet.
  • More restrictive setbacks may apply for sites impacted by critical areas.

Other conditions may apply if the property owner participates in a King County program. For more information, see www.kingcounty.gov/environment/wlr/topics.aspx. and www.kingcounty.gov/environment/stewardship/sustainable-building/land-stewardship.aspx.

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