Building permits, zoning and septic rules in Ferry County, Washington

Unincorporated Ferry County requires a building permit for permanent buildings and additions, subject to exceptions; approved final plans must address the site, sewage, drainage, access, foundation and other project details¹. Washington’s building code applies in every county and city, subject to statutory exceptions¹¹. Ferry County provides application packages for homes, mobile homes, outbuildings, commercial projects, and plumbing and mechanical work¹⁰. Permit-required work must remain accessible for inspection and pass final inspection before occupancy². A person working on their own property or personal residence may qualify for Washington’s contractor-registration exemption, but contractor work on their own property for sale, demolition or lease is excluded; building, electrical, plumbing and septic permits still apply⁹. False information used to obtain the exemption can result in building-permit forfeiture⁹. Ask the Building Department for current building-permit fees¹⁰.

For unincorporated Ferry County, start with the Ferry County Building Department for building applications and inspections¹⁰. Inside Republic, building-permit applications come from Town Hall; septic remains with Northeast Tri County Health District^4,5. Ferry County’s construction design data specifies a minimum roof snow load of 40 psf countywide, suggests 55 psf or more at elevations of 3,000 feet or more, sets a 110 mph basic wind speed and requires a 30-inch minimum frost depth¹⁰. Planning answers lot-size, density, Curlew Lake and resource-land questions and administers floodplain development permits^7,12. Ask Public Works about the county-road approach process, whose operative requirements we could not confirm¹³.

Unincorporated Ferry County has no conventional zoning that limits what may be built, but minimum lot sizes and residential density controls apply³. On lots larger than 2.5 acres, residential development is limited to 1 single-family dwelling per 2.5 acres and/or 1 business use per lot³. New subdivision lots need at least 12,500 square feet with community water and sewer, 1 acre with community water and individual sewer, or 2.5 acres with individual water and sewer³. Curlew Lake Sub Area Plan controls and Agriculture or Forest Land of Long-Term Commercial Significance designations impose distinct density and parcel-division rules³. Designated agricultural land generally cannot be divided below 20 acres and allows no more than 1 residence per 20 acres, with exceptions for extended family and full-time employees who work and live on the farm³. Before buying or dividing land, ask Planning which designations apply; septic suitability also affects proposed subdivisions^3,12.

Northeast Tri County Health District administers on-site sewage in Ferry County and permits systems with design flows under 3,500 gallons per day^5,14. Submit the application, ownership verification, site plan, directions and completed Planning Office site analysis; NETCHD reviews the site and design before issuing an installation permit¹⁵. Installation may begin only after the permit is issued, and the permit remains valid for 3 years⁵. Before the system is covered, NETCHD requires a final inspection and completed as-built form; schedule the inspection with at least 48 hours' notice^5,15. Only 7.2% of Ferry County soils are rated “not limited” for a conventional drain field; that calls for a site evaluation, not a conclusion that septic is impossible¹⁶. Residential pit toilets are limited to parcels of at least 20 acres¹⁷.

Washington defines a tiny house or tiny house on wheels up to 400 square feet, including its kitchen, bathroom and sleeping or living area, but the home must meet the state building code and local foundation, installation and location requirements⁸. Ferry County's materials do not confirm a local tiny-home occupancy rule, minimum dwelling size or accessory-dwelling rule, so take the parcel and proposed design to the Building and Planning departments before purchase^10,12. Washington's definition of a recreational vehicle describes temporary, transient quarters that are not a primary residence; it does not grant permission for residential use on private land¹⁸. Ferry County's documented RV-park standards require separation between RV spaces and setbacks from property lines and public rights-of-way, but those standards do not authorize long-term RV occupancy outside an approved RV park¹⁹. Ask Planning before treating an RV as temporary housing or a permanent dwelling¹².

1. Ask the Planning Department to confirm the parcel's minimum lot size, density, Curlew Lake controls and any agriculture or forest designation^3,12.
2. Complete the appropriate Building Department package, include the required final plans and request the current fee schedule^1,10.
3. If the site is in a mapped special flood hazard area, obtain a floodplain development permit from Planning before work begins⁷.
4. Submit ownership verification, a site plan, directions and the completed Planning Office site analysis with the septic application; obtain design approval and the installation permit before installing the system^5,15.
5. Keep permit-required building work visible for inspection, and arrange septic inspection before the system is covered^2,15.
6. Ask Public Works about a county-road approach; a connection within a state-highway right-of-way requires written WSDOT permission^13,20.

Only 7.2% of Ferry County soils are rated “not limited” for a conventional drain field; a site evaluation can identify whether the parcel needs an engineered system¹⁶. Just 28.7% of county land has a slope of 15% or less, and 75.4% is forested, so inspect the building pad, driveway route and clearing needs¹⁶. Washington exempts domestic groundwater use up to 5,000 gallons per day per project from a water-right permit, aggregating multiple wells; other water-law and local limits still apply²¹. Submit a notice of intent to Ecology 72 hours before drilling; the notice does not approve water use²¹. Ferry County building-permit applicants must show an adequate potable water supply¹. Ask Planning about resource-land and Curlew Lake controls and check mapped flood hazards before siting improvements^3,7,12. Ferry County’s effective property-tax rate is about 0.7%, and its median annual property-tax bill is about $1,792¹⁶.