Imperial Beach ADU Regulations & Zoning

If you have more than one existing dwelling unit on your property, use these regulations:

Lots with existing or proposed multiple-family dwellings (e.g. two or more attached units on one lot, like a duplex):
1. Up to two detached Accessory Dwelling Units, and
2. The conversion of portions of multiple-family structures that are not used as living space to create at least one internal Accessory Dwelling Unit, or up to twenty-five percent of the number of existing dwelling units as internal Accessory Dwelling units

Lots with more than one existing or proposed single-family dwelling (e.g. two houses on one lot): One internal or detached Accessory Dwelling Unit per lot.

Effective Jan 2025 (SB1211): Multifamily property owners are permitted to build as many ADUs as there are existing units, with a maximum of eight detached ADUs. This change is due to California state law and will pre-empt existing local laws that are not brought into conformance.

The maximum height for detached or attached ADUs is 16 feet, unless one or more parking spaces are provided on the ground floor of the ADU, in which case the maximum height shall be the same as the primary dwelling in the underlying zone. This basically means you can build an ADU over a garage.

Additionally, state law allows up to 20′ tall if within 1/2 mile of transit, or if attached to main home.

ADUs shall utilize the same or complementary architectural style, exterior materials, and colors as the existing or proposed primary dwelling, and the quality of the materials shall be the same or exceed that of the primary dwelling.

For most zones in Imperial Beach, no building shall be located less than ten feet from any other building on the same lot. (Ord. 94-884; Ord. 601 § 1, 1983).

Imperial Beach does not explicitly state if a soils report is required.

Yes, accessory dwelling units developed within the coastal zone of Imperial Beach are subject to the approval of an Administrative Coastal Development Permit by the community development department. No public hearing shall be required for permit approval. The additional cost for a coastal permit is $600.

Note that some areas of Imperial Beach that are in the coastal zone are regulated by the California Coastal Commission, which means the permit is applied for differently and may have higher fees.

Read more about ADUs in the coastal zone. Also see the City of Imperial Beach’s overview of What Triggers a Coastal Permit for ADUs.

Yes, you can stack detached ADUs on top of each other on multifamily properties (confirmed by an associate planner in Imperial Beach via email in June 2024).

Yes, as long as they comply with the underlying zoning, you may attach two ADUs.

Non‐livable space within existing multi‐family structures may be converted into an ADU. Examples of areas that can be converted include storage rooms and garage spaces. The maximum number of ADU allowed in a multi‐family structure is equal to 25% of the number of existing multi‐family units in the structure. A minimum of one conversion ADU is allowed.

If a parking space is required, it may be located within the setbacks and in an existing driveway as tandem parking. Parking spaces don’t need to be replaced when a garage, carport, or covered parking structure is demolished in conjunction with the construction of an ADU or converted to an ADU.