Irvine, CA Accessory Structures: Shed & Carport Rules (2026)

Zoning Ordinance Sec. 3-5-1 sets the residential rules for a minor accessory structure: the code's term for a garden shed, storage shed or child's playhouse that is detached from the main house and non-habitable. Six requirements apply together: the structure is permitted only within the rear yard area; it is capped at a total maximum area of 250 gross square feet; no more than 50 percent of a required setback area may be covered by minor accessory structures; the structure's maximum height is 12 feet or one story, whichever is less; it must comply with all building codes and the zoning ordinance generally; and its footprint still counts toward the site's overall coverage limit in Chapter 3-29, which caps coverage from every structure on the lot combined.

The same section draws a hard line against confusing a shed with a garage apartment: it expressly notes that "accessory dwelling units are a separate land use" subject to Chapter 3-26, not the Sec. 3-5-1 shed standards, so a converted or newly built ADU is not limited to 250 square feet. A parallel commercial/industrial track in Sec. 3-5-1(B) lets an established commercial, industrial, office or institutional use add a minor accessory structure of up to 10 percent of the principal use's area, provided it stays incidental to that use, generates no added trip demand, and complies with all codes; if the principal use required a conditional use permit, adding the accessory structure can trigger a modification of that permit under Chapter 2-9 or Chapter 2-19. Enforcement of every zoning ordinance provision, including Sec. 3-5-1, is assigned to the Director of Community Development under Sec. 2-10-1.