Name the ADU type before reading the rule.

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.

Write the proposed size and location on the same page as the property type. Otherwise a general answer can be applied to the wrong project.

Put records beside what you can see on site.

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.

Old permits can explain an addition or garage change, but the crew still needs to compare those drawings with what is standing today.

Measure the proposed building area.

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.

If a standard affects the footprint or height, show it on the working drawing and identify who confirmed the interpretation.

Permit questions often become construction questions.

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.

Write down where each answer came from.

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.

Save the City page, response date, and drawing that went with the question. For help organizing the construction side, call (949) 503-8004 or return to Costa Mesa ADU Contractor.

Where to confirm information about the rules that affect an ADU.

The rules that affect an ADU should be checked against current City and state pages; record the address, drawing, and date covered by the answer. For the rules that affect an ADU, check the City of Costa Mesa ADU page, California HCD, and CSLB hiring guidance. For the rules that affect an ADU, our Costa Mesa ADU Contractor homepage shows how it connects with the rest of the project.