Planning & Building

Yes. A Building Permit is required.

Visit Construction Permit Application for the permit process.

An attached or detached residential dwelling unit that provides complete independent living facilities for one (1) or more persons and is located on a lot with a proposed or existing primary residence. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family or multi-family dwelling is or will be situated.

An ADU also includes the following:

• An efficiency unit.
• A manufactured home, as defined in Section 18007 of the Health and Safety Code.

A unit that is no more than 500 square feet in size and contained entirely within a single-family residence. A JADU may include separate sanitation facilities or may share sanitation facilities with the existing structure.

This guide serves to help you determine whether an accessory dwelling unit (“ADU”) can be established on a parcel or lot (“site”) under the State ADU Law (Coastal Zone). Although many of the factors that must be considered in ADU development are included in this guide, on any given site, there may be circumstances specific to the site or requirements from other agencies/departments that may require attention or prevent ADU development. Nothing in this guide shall be misconstrued or interpreted to guarantee approval of an application to establish ADU(s). 

This guide does not replace or supersede the provisions of applicable laws, codes, and policies. Where the information in this guide conflicts with applicable laws, codes, and policies, the provisions of the applicable laws, codes, and policies shall control. 

ADUs may be permitted in the following land use categories:

It would depend on the contract language. Contracts should be review by Planning on a case-by-case basis.

ADUs shall not be allowed within the following areas:

• Tract or Parcel Map Conditions
  • Any parcel within a tract or parcel map that contains conditions prohibiting accessory dwellings.
• Regional Water Quality Control Board Exclusion
  •  All areas of the County where the Regional Water Quality Control Board has issued a notice of resource constraints through moratoria or other means.

COMMUNITY WATER

A will-serve letter from the water purveyor will be required. Note: Some water purveyors, such as Cambria CSD, may not be issuing any new water connections. Please contact the water purveyor directly for more information.

ONSITE WELL

A well test in compliance with Section 19.07.040(b) will be required.

SITES SERVED BY COMMUNITY SEWER

A will-serve letter from the wastewater service provider will be required. Note: Some wastewater service providers, such as Cambria CSD, may not be issuing any new wastewater connections. Please contact the wastewater service provider directly for more information.

SITE SERVED BY ONSITE WASTEWATER TREATMENT SYSTEMS

Sites served by onsite wastewater treatment systems (such as septic systems) will have to satisfy the requirements of the Building Code (Title 19), which may include standards for lot size. For sites served by onsite wastewater treatment systems, such as septic systems, please contact Michael Byrd to determine if those requirements, which may include lot size standards, can be satisfied.

Michael Byrd

Environmental Health Specialist

Phone: (805) 781-1537

Email: [email protected]

The installation of fire sprinklers will not be required in an ADU if fire sprinklers are not required for the primary residence. However, if the ADU is attached to other structures that require fire sprinklers, installation of fire sprinklers may be required.

A zoning clearance is required, which takes place once a construction permit is applied for.  To apply for a construction permit, please visit Construction Permit Application.

Although the County is reviewing ADU applications based on State ADU Law in the Coastal Zone, the California Coastal Commission may appeal or consider appeals with respect to the existing Coastal Zone ADU Ordinance (County of San Luis Obispo Code Section 23.08.169).

As such, an application that is consistent with both the existing Coastal Zone ADU Ordinance and State ADU Law would likely be more successful in securing the permits necessary to establish an ADU, than an application that is consistent with only the State ADU Law.

Coastal Zone and Inland Area