Can I build ADU in a coastal zone?

California Coastal Commission (CCC) is in line with the state in supporting smaller and more affordable housing to combat the statewide availability of smaller and more affordable housing units in the area.

Though coastal zones have lots of building restrictions to preserve the natural beauty and integrity of the coast, you can still build an ADU if it complies with the new Coastal Act and the requirements of the Local Coastal Program (LCP) for the protection of coastal resources and public recreational use.

An attached ADU or that converted through of existing space may be exempt from the requirement of obtaining a coastal development permit (CDP); however, the construction of a detached unit that adds livable square footage to your property is likely to require a CDP unless indicated otherwise.

Can I Build An ADU? Check if your address is eligible for an ADU here: ADU Eligibility Checker

Construction Consulting Service can help you navigate the process of obtaining an ADU permit for your coastal property.

Here is everything you need to know about ADUs in the coastal zones.

How Are ADU/JADU Regulations Different for Coastal Properties?

Unlike properties in the inland areas, which require obtaining a permit from the local building department to build an ADU or JADU, those located in a coastal zone are subject to the regulation of an LCP besides the local zoning laws and ordinances.

Local coastal development authorities need to obtain approval from CCC for any proposed changes in an LCP before the amended regulations take effect.

A CDP cannot be issued for a proposed ADU that is not in line with the current requirements of LCP until the proposed amendment in the program is approved by CCC.

You are likely to be permitted for building an ADU in a coastal zone if the proposed dwelling or property is not located in;

  • Wet beach (a land seaward of the mean high tide line)
  • Environmentally sensitive habitat or scenic areas
  • Areas of natural vegetation
  • Very High Fire Hazard Severity Zones
  • Within 50 feet of the edge of a coastal bluff or stream
  • Areas determined to have critically short water supply by CCC.
Coastal Zone ADU

ADUs in the Coastal Zones: Waivers & Exemptions

Determine if the Proposed ADU Is Exempt from CDP Requirements

Generally, ADUs that are created through the conversion of an existing space, i.e., garage, or that share at least one wall with the existing structure may qualify as part of a single-family residential structure improvement.

The construction of a standalone unit, however, usually requires a CDP unless there is an existing waiver program in place.

Waiver and Exemption

If Not Exempt, Determine If a Waiver for Is Appropriate for the Proposed ADU

In case the coastal program contains a waiver provision and the proposed secondary dwelling qualifies to obtain a CDP wavier, the permit requirement can be waived for the unit by the local government.

CCC generally allows a waiver for proposed freestanding secondary units if the authority’s executive director believes that it won’t have any adverse effects on coastal resources and is in line with the policies of the commission.

Some local coastal programs do not include a wavier provision; however, there may be similar procedures in place to expedite the approval of the secondary units.

If the proposed ADU is not subject to a CDP waiver or exemption, the local government may seek an amendment in the program from CCC in order to authorize the appropriate procedure.

If the Proposed ADU is Neither Exempt Nor Subject to a Waiver: A Review CDP Application Has to Be Filed with CCC

If your proposed dwelling unit is detached from the primary structure, is not subject to an exemption, wavier, or an expedited approval process but qualifies as appealable development, a review CDP application is needed to be filed with CCC for consistency with the LCP requirements.

The local government is obliged to issue the public notice for any ADU coastal permit applications in accordance with the requirements of local coastal program. Once the notice of the final local action is issued by the local government, it should be submitted to local coastal commission. An appeal seeking issuance of CDP for the ADU can be then filed with the CCC.

Need Help Navigating ADU Regulations in a Coastal Zone? 

If you have any questions about building an ADU or JADU in a coastal zone, reach out to us at (323) 405-8909, and we will get back to you with comprehensive and accurate information.