Ada County, ID Building Safety: Building Permits (2026)

1 of the 2018 International Building Code, as amended by Ada County Code 7-2-4, requires any owner or an owner's authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to install, alter, repair, remove or replace a gas or mechanical system, to first apply to the building official and obtain a permit before starting work. The permit attaches to the property itself, not to the applicant, so it survives a change of ownership; the applicant is treated only as the property owner's representative and doesn't personally control the permit.

2 lists 15 specific 'Building' exemptions from that permit requirement: one-story detached accessory structures such as tool sheds and playhouses under 200 square feet and 12 feet tall; fences up to 6 feet high; retaining walls up to 4 feet measured from the footing (unless they hold back Class I, II or IIIA liquids or a surcharge); water tanks up to 5,000 gallons with a height-to-diameter ratio no greater than 2:1; sidewalks and driveways under 30 inches above grade; painting and similar finish work; temporary movie and stage sets; prefabricated above-ground pools under 24 inches deep and 5,000 gallons; agricultural shade-cloth structures; playground equipment; certain window awnings and low fixtures; temporary construction-support buildings that come down before occupancy; and painted or manufactured signs up to 32 square feet or 6 feet tall.

3 using whichever is greater: the applicant's stated project value or the county's own fee-schedule calculation, and that valuation is what the Ada County Building Permit fee is charged against.