Legalizing an unpermitted ADU in Del Mar

Del Mar has a specific path for this: the ADU Amnesty Program in DMMC §30.91.080 (Del Mar Municipal Code Chapter 30.91 (June 2025)).

The Amnesty Program

Owners with unpermitted ADUs existing as of April 15, 2021 can apply to obtain permits and legalize the unit. Applications are processed through the Administrative Coastal Development Permit procedure.

State protections

• Gov. Code §66331: for ADUs built before January 1, 2020, the city must delay building-standard enforcement on request, subject to Health and Safety Code §17980.12
• The city's 2025 affordable ADU survey said responses wouldn't be used for code enforcement

Del Mar's nonconforming rule

If legalizing involves redevelopment of a structure nonconforming for geologic setbacks, public views, coastal access or habitat buffers, the city requires those conditions to be corrected.

Step by step

1. Confirm the unit existed by April 15, 2021
2. As-built survey and drawings
3. Gap list against Chapter 30.91
4. Amnesty application with administrative CDP
5. Inspection and corrections
6. Deed restriction and final

What legalization usually involves

Most unpermitted units need some combination of egress windows, smoke and carbon monoxide alarms, electrical work, a compliant kitchen with a real cooking appliance, and fire separation. In Del Mar, add the coastal layer: the amnesty application goes through the Administrative CDP, so coastal setbacks, protected trees and flood rules come into play.

Checklist

• Evidence the unit existed by April 15, 2021
• As-built plans
• Kitchen and bath meet the ADU definition
• Coastal setbacks checked
• Deed restriction recorded

State rules that help

The HCD handbook notes fire sprinklers can be required only if the house requires them, and creating an ADU can't trigger sprinklers for the house. Disclose any open code enforcement case on the application.

Also checked Oct 14, 2026: Del Mar ADU Application Packet (Rev. 2024) · HCD ADU Handbook (March 2026).

Sources, checked Oct 14, 2026: Del Mar Municipal Code Chapter 30.91 (June 2025) · Gov. Code §66331.