ADU guide
Detached vs Attached ADU
An attached garage is connected to the home; a detached garage stands separately. The distinction changes where an entry can be placed and how a professional might route utilities. It also affects which unit type the local agency considers.
Requirements depend on your property and the agency reviewing it. Confirm current details with that agency before finalizing plans.
Questions to consider
- An attached conversion shares a physical connection with the house; compare interior access and privacy with the desired layout.
- A detached conversion stands apart; map the route for water, drainage, and power from existing connections before deciding where fixtures go.
- In the City of San Diego, the ADU bulletin describes ADUs as attached or detached and a junior ADU within a single dwelling or attached garage.
- Compare proposals for any new utility runs, access changes, and restoration; neither option is automatically cheaper.
- Confirm the appropriate unit type, applicable requirements, and property-specific design with the reviewing agency.
Official resources
Common questions
Can an attached garage be considered for a junior ADU?
The City of San Diego describes junior ADUs in a home or attached garage. Confirm requirements for your address and project with the reviewing agency.
Does a detached garage always cost more?
Not necessarily. Existing conditions and the proposed work vary; request estimates based on the actual building and utility routes.
San Diego County projects
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