Eureka, CA Accessory Structures: Shed Rules (2026)

Humboldt County does not have a separate shed-specific ordinance; sheds and other small accessory structures are regulated under the California Building Code (CBC) as adopted by reference in Humboldt County Code section 331-11, plus the zoning setbacks that apply to accessory buildings in each district. CBC section 105.2 exempts from a building permit 'one-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 120 square feet.' Permit-exempt status does not excuse zoning compliance; the shed must still meet the underlying zone's setbacks, height, and lot-coverage standards. Section 314-43 of the Inland Code states that accessory buildings are permitted as appurtenant to any permitted use, but on residentially-zoned property (RS, R-1, R-2, R-3, R-4) and in Unclassified (U) Zones designated for residential use, no accessory building may be erected and no accessory use conducted until the main building is erected and occupied (or unless a Special Permit is secured). Sheds and other detached accessory buildings on parcels 1 acre or larger are also subject to the Humboldt County Fire Safe Regulations defensible-space setback in section 3115-2: a 30-foot setback from all property lines and the road centerline, except that a detached accessory building constructed of non-combustible or fire-resistive materials may be located within the 30-foot setback if it is at least 20 feet from any other building. Any electrical, plumbing, or gas utility serving the shed (lighting, outlets, hose bibbs, etc.) requires the relevant trade permit, even when the shed itself is permit-exempt.