Costa Mesa ADU requirements: start with the property.

What to bring into the first discussion.

Identify the property type and proposed unit before applying a rule. A detached ADU, conversion, attached unit, and JADU do not create the same plan or construction scope.

Look closely at the existing conditions.

Collect parcel records, prior permits, surveys, easements, and association documents that may affect the proposal. Compare those records with visible conditions because old alterations are not always reflected in one source.

Connect the decision to the full scope.

Measure the proposed location, building relationships, access, and yard features. Setbacks, height, floor area, fire access, parking, and other standards require current property-specific confirmation.

Use current sources and responsible professionals.

Utilities, drainage, grading, and existing service capacity are construction questions as well as permit questions. Assign who investigates them and how the result will change the drawings or estimate.

Read the related Costa Mesa ADU services, cost guide, and permit guide for the construction context.

Choose a practical next step.

Use current City and California sources. Record the date checked and the person or agency that answered a project-specific question so the team does not rely on an old summary.

Return to Costa Mesa ADU Contractor or call (949) 503-8004 when you are ready to discuss the property.