How Anaheim Handles Accessory Structures: A Practical Guide

Anaheim maintains 197 local ordinances across all categories, and 4 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Anaheim falls on the strict-to-permissive spectrum compared to other cities.

ADU Impact Fees

Anaheim exempts accessory dwelling units under 750 square feet from park, water and other agency impact fees under Municipal Code Section 17.08.240. Larger ADUs pay fees prorated to the primary home's square footage, not the flat per-unit rate charged to new houses.

Key details: Exemption threshold: Under 750 sq ft: no impact fee. Larger ADUs: Fee prorated to primary unit's sq ft. State authority: Gov. Code § 66324. Last amended: Ord. 6625, April 21, 2026. Fees covered: Local agency, special district, water corp.

There is no separate penalty section for miscalculated ADU fees; impact fees are collected as a condition of building permit issuance under the Subdivision Map Act procedures in Sections 17.08.270 through 17.08.290, so a permit will not be finalized until the correct fee (or exemption) is confirmed by the Planning and Building Department. Disputes over whether an ADU qualifies for the under-750-square-foot exemption are resolved administratively before permit issuance, not through a citation process.

Anaheim is more permissive than most cities when it comes to adu impact fees. That said, there are still limits.

Shed & Carport Rules

Anaheim caps garden sheds, storage sheds, garages and other accessory structures in single-family zones at one story or 16 feet, whichever is less, under Section 18.04.070.030. Sheds built entirely outside required setback areas that match the main house's design can exceed that limit, and structures encroaching into setbacks face further height limits under the Table 4-J encroachment standards.

Key details: Height limit: One story or 16 feet, whichever is less. Exception: No cap if fully outside required setbacks. Floor-area cap: Cannot exceed main house's minimum livable area. Lot coverage: Sheds count toward 40-50% zone lot-coverage cap. Governing section: AMC 18.04.070.030 (Structural Heights).

A shed or other accessory building built over the 16-foot/one-story height limit, or that exceeds the lot's cumulative accessory floor-area or lot-coverage cap, is a zoning violation subject to the Code's general penalty in Section 1.01.370, a misdemeanor with fines up to $1,000, up to six months in jail, or both. The City can also require the structure be modified or removed to bring the lot into compliance before permits on the property will be finaled.

ADU Rules

Anaheim allows one accessory dwelling unit and one junior accessory dwelling unit by right on any single-family lot, on top of the primary home, under Section 18.38.015. A detached unit can reach 1,200 square feet, an attached unit up to 850 square feet for a studio or one bedroom, with 4-foot side and rear setbacks.

Key details: Units allowed: 1 ADU + 1 Junior ADU per single-family lot. Total unit cap: 4 units max including primary house. Detached ADU size: Up to 1,200 square feet. Attached ADU size: Up to 850-1,000 square feet by bedrooms. Setbacks: 4 feet side and rear for detached ADU.

An ADU built without the required City permits, or that exceeds Section 18.38.015's size, height or setback standards, is subject to the Code's general enforcement and misdemeanor penalty under Section 1.01.370: up to a $1,000 fine, six months in jail, or both, with continuing violations charged separately for each day. Non-conforming units can also be denied final occupancy approval until brought into compliance.

Garage Conversions

Anaheim lets homeowners convert an existing garage into livable space as an Accessory Dwelling Unit without meeting lot coverage, setback, height or building separation rules. If the garage door faces a public street, the door itself must stay in place even if it no longer opens.

Key details: Governing section: AMC Sec. 18.38.015.140. Setback/height exemption: Lot coverage, setback, height, separation waived. Street-facing garage door: Must remain, need not function. Parking replacement: Not required when garage converts to ADU. Application review: 15 days complete, 60 days decide.

A garage conversion built without a permit is treated as an unlawful ADU under Sec. 18.38.015.130 unless the Planning and Building Director finds it meets the section's standards; pre-2020 unpermitted units get a narrow exception from denial for pre-existing building-code violations under subsection .1301, but the City can still require correction under .1302 where needed to meet Health and Safety Code Sec. 17920.3 habitability standards. Removing a street-facing garage door instead of retaining it as required by .0904 is a code compliance violation enforced by the Planning and Building Department.

The Bottom Line

Anaheim's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Anaheim is broadly strict or permissive.

These rules come from Anaheim's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.