Understand the City program before assuming eligibility.
Costa Mesa's Safe ADU Legalization Program describes a route for certain unpermitted ADUs and JADUs constructed before January 1, 2020, subject to safety standards and program requirements. That date alone does not establish eligibility or approval for a particular unit.
Read the City's Safe ADU Legalization Program information and discuss the actual property with the City and qualified professionals.
Gather the existing story of the space.
Collect available plans, permits, records of construction, photographs, and information about known alterations. Document how the space is currently arranged and used. Identify visible concerns and questions about services, structure, and the relationship to the main house.
Keep known facts separate from assumptions. If the construction date or permit history is uncertain, record that uncertainty and ask what evidence the reviewing authority needs. Do not alter records or present a guess as a confirmed project history.
Define the review before pricing repairs.
An existing-condition review can identify work needed to address safety and approval requirements. The responsible professionals should explain what was observed, what needs further investigation, and what scope follows from the findings.
For the construction proposal, separate investigation, documented corrective work, discretionary upgrades, and items still dependent on review. Treating everything as a simple cosmetic remodel can hide the work that actually needs to be resolved.
Connect the findings to a buildable scope.
Once the required work is understood, coordinate drawings, permit responsibilities, access, and the construction sequence. If anyone occupies the unit, discuss how the process affects use of the space with the responsible authorities and project professionals.
Our ADU construction process and ADU project budget framework help organize the next decisions. For a planned new conversion, start instead with the garage conversion service guide.