Building permits, zoning and land rules in Grant County, Washington

Dwellings and most buildings in unincorporated Grant County require county-issued building permits and inspections before use or occupancy¹. The Building Division reviews applications under Washington State Codes, including the State Energy Code¹⁰. The applicant, owner or contractor must schedule the inspections listed on the project’s inspection card and obtain approval¹¹. Grant County will not issue a residential Certificate of Occupancy if missed inspections cannot be performed because the work was covered¹¹. A qualifying owner-builder may be exempt from contractor registration when the work is not for sale, demolition or lease; building permits still apply⁷.

Grant County's Building Division serves unincorporated construction at 264 W Division Avenue, Ephrata, WA 98823, and 509-754-2011, ext. 3001¹⁰. Planning questions go to the Planning Division at 509-450-1118¹². Commercial and residential building applications must be submitted electronically, with an exception for small accessory structures; applications go to Planning, Fire Marshal, Public Works, Health District and Building Division as applicable¹³. The county portal accepts applications, and deposits depend on the project and structure size¹³. Grant County’s published building-permit fee schedule updates each July, and online card payments carry a 2.7% bank convenience fee¹³.

Grant County zoning governs unincorporated land; district standards determine allowed uses, minimum lot area, setbacks and building height^2,14. Inside Warden and Royal City, each city sets its own zoning^15,16. Local septic review remains with Grant County Health District for systems within its service area and flow threshold³. County zoning maps may not show every overlay; Planning determines applicable overlays during project review². Shoreline jurisdiction can extend 200 feet landward from the ordinary high-water mark and generally limits building height to 35 feet¹⁷. We could not confirm a general minimum principal-home size; ask Planning for the parcel’s requirements¹².

Grant County Health District oversees local septic systems with wastewater flows under 3,500 gallons per day³. Except for minor repairs, obtain a septic permit before installation, repair, modification, connection or expansion begins⁵. Septic installation requires site and soil evaluations, and most systems require a GCHD-certified installer¹⁸. For property under county authority, file the county building application before a new septic application; most septic repairs do not follow that sequence⁴. The local installation-start permit lasts 2 years from application approval⁴. Off-grid development without sewer service still needs an approved septic system or other treatment process¹⁹. About 34.7% of county soils lack severe limitations for conventional drain fields, making site evaluation a purchase priority²⁰.

We could not confirm general long-term RV or temporary-camping rules on private land in unincorporated Grant County; ask Planning before placing a unit¹². On-site tiny houses of 400 square feet or less, excluding sleeping lofts, follow the single-family building-permit process⁶. Wheeled tiny houses can qualify as permanent dwellings; Washington-built and sold units need state approval and an insignia, while out-of-state units need Development Services review before application⁶.

Grant County allows an ADU outside an urban growth area subject to zoning, adequate water and sewage capacity, and permanent residential use rather than transient rental⁸. Detached ADUs must be within 150 feet of the principal dwelling and share access⁸. Detached ADUs are prohibited on nonconforming lots under 1 acre and in RR1 on lots under 5 acres; manufactured or modular detached ADUs require at least 10 acres⁸. Outside an urban growth area, ADUs must be at least 192 square feet and no larger than 1,296 square feet or 55% of the principal dwelling’s floor area, whichever is smaller⁸.

1. Ask Planning to confirm the parcel’s allowed residential use, zoning, overlays, setbacks and lot-area standard².

1. Arrange water and wastewater service; city water or sewer needs a city confirmation letter, and the Health District reviews potable water and septic¹³.

1. Submit the electronic building application through the county portal, then coordinate a new septic application and site evaluation with the Health District^4,13,18.

1. Obtain an approach permit before constructing a county-road connection, or state approval for new or changed-use state-highway access^13,21.

1. Obtain floodplain approval when required; Grant County will not issue the building permit until the Floodplain Development Permit is approved⁹.

1. Schedule required inspections before covering the work and obtain the residential Certificate of Occupancy¹¹.

Ask Planning about any proposed land division because Grant County regulates subdivisions²². Floodplain development approval covers grading, fill and excavation as well as buildings; a proposed structure in the floodplain may need a certified elevation certificate⁹. The county also assesses whether frequently flooded land may lie within 100 feet of proposed activity²³.

Washington’s domestic groundwater water-right permit exemption covers up to 5,000 gallons per day per project, aggregating multiple wells, but remains subject to other water-law limits; a drilling notice of intent is due to Ecology 72 hours beforehand and does not approve water use²⁴. Ask Grant County Health District to confirm potable-water acceptability for the building application¹³. Grant County’s effective property-tax rate is about 0.8%, and the median annual bill is about $2,268²⁰.