Bonner County, ID Accessory Structures: Shed & Carport Rules (2026)

The Board of County Commissioners regulates accessory buildings through Title 11 of the Bonner County Revised Code. Section 11-101 requires a building location permit from the planning department before any structure is erected, placed or enlarged in unincorporated Bonner County, and section 11-104 sets a lighter track for small structures. A small structure is a detached, non-habitable accessory building used as a tool or storage shed, playhouse, carport, shop, agricultural building, garage or similar structure whose floor area does not exceed 1,080 square feet. It cannot have sewage disposal utilities, and it cannot be a place of employment, except structures used for agricultural direct marketing activities. The ceiling follows the building: additions cannot be added to a previously exempted structure if they would push the floor area past 1,080 square feet, and an open shell lean-to or open shell deck addition to a residential or residential accessory structure stays under the same 1,080 square foot limit.

The definition of "structure" in section 11-219 holds a second, smaller threshold. Detached tool and storage sheds, playhouses and similar uses with a floor area that does not exceed 400 square feet are listed as exceptions to the structure definition. So is an addition to an existing residential accessory structure used solely for storage or agricultural uses, such as woodsheds, lean-tos, greenhouses and general storage, provided the addition totals no more than 400 square feet, has no sewage disposal utilities and does not push the structure past 400 square feet. Those exceptions are expressly subject to the land use standards in Title 12, and section 11-103 adds that an exception from permit requirements does not authorize work in violation of the Code or any other county, state or federal law. A shed that skips the permit still has to meet the setbacks and use rules of its zoning district.

A small structure permit stays alive only if work starts. It expires and becomes null and void if the work is not commenced within one year of the issuance date, or if work is suspended or abandoned for more than one year after it begins. The structure also has to comply with Title 12 and Title 14, the flood damage prevention title. Under section 11-105 the application carries a site plan showing distances from the building's greatest architectural projections to each property line and to environmental features such as wetlands, shorelines and slope, plus a copy of the recorded deed and a description of the intended use. The Board sets filing fees by resolution under section 11-108, and the Planning Department keeps the schedule available for public inspection.