What you can build

Imperial Beach ADU Regulations & Zoning


Size and Separation

Maximum size 1,200 square feet

Side/rear setbacks 4 feet

Two story Yes, above garage

Building separation 10 feet

Additional Requirements

Soils Report No

Building Verification Survey No

Coastal permit (in some areas) Yes

Stormwater Mitigation No

Number of ADUs Allowed

How many ADUs can you build in Imperial Beach?

On single-family residential lots in Imperial Beach, you may build one ADU (either attached or detached) and one Junior ADU (JADUs have an owner occupancy requirement and must be converted from existing space within the primary residence).

How many ADUs does Imperial Beach allow for multifamily properties?

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.

ADU Size & Building Constraints

What size ADU can you build in Imperial Beach?

Imperial Beach allows at least 850 square feet for ADUs with one or fewer bedrooms and 1,000 square feet for units with two or more bedrooms. Additionally, you may build up to 1,200 square feet if no existing off-street parking is removed as part of the construction of the Accessory Dwelling Unit and one off-street parking space is provided in addition to the minimum off-street parking spaces required.

What is the height requirement for an ADU in Imperial Beach? Can you build a 2-story ADU in Imperial Beach?

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.

What are the requirements of the exterior of the ADU?

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.


What is the setback requirement for an ADU in Imperial Beach?

For Accessory Dwelling Units with a height of 16 feet or less, side and rear setbacks shall be four feet or consistent with the requirements of the underlying zone. For ADUs with a height over 16 feet, side and rear setbacks for the portion of the building that is higher than 16 feet shall be consistent with the setback requirements of the underlying zone.

What is the minimum distance the ADU must be from existing structures?

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).

Additional Requirements

Does Imperial Beach require in-person submission of plans for an ADU?

No, Imperial Beach allows digital submission of applications for an ADU.

Does Imperial Beach require a soils report for an ADU?

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

Does Imperial Beach require coastal development permits?

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.


How many ADUs does Imperial Beach allow for multifamily properties?

Two detached ADUs on lots with existing or proposed multiple-family dwellings.

Can you stack detached ADUs on top of each other?

It has not yet been determined if you can stack detached ADUs on top of each other on multifamily properties.

Can you attach two ADUs to each other in Imperial Beach?

Yes, as long as they comply with the underlying zoning.

Can you convert existing space to an ADU?

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.


What is the parking requirement for an ADU in Imperial Beach?

A parking space is not required for an ADU in any of the following instances:

  • Within a one-half mile walking distance from public transit, which includes bus stops.
  • Within an established historic district.
  • Converted from the existing space of a primary residence or accessory structure, or are attached to an existing or proposed primary residence.
Where can a parking space be located?

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.