El Dorado County, CA Accessory Structures: Garage Conversions (2026)

Section 130.40.300(C)(3)(c) singles out 'Converted Existing Space' as its own category of accessory dwelling unit, separate from new attached or detached construction. Any legally permitted residential accessory structure, the code lists garages, pool houses, cabanas, artist studios, barns, and workshops as examples, can be turned into an ADU as long as the conversion meets the county's building code and the zoning provisions of Title 130.

The conversion gets real relief from the standards that apply to new ADU construction. No setback is required for converting an existing living area or legally permitted accessory structure, or for a replacement structure built in the same location and to the same dimensions as the original. The floor-area caps in Table 130.40.300.1, which otherwise limit detached ADUs to between 850 and 1,600 square feet depending on lot size, do not apply to a conversion: the code gives the example of a 3,000-square-foot barn converting to an ADU without hitting a size ceiling, height limit, setback, architectural review, or landscape standard, though it still has to meet building code for permanent occupancy.

Conversions also skip replacement parking. If turning the garage into living space removes covered parking that was required for the primary house, the county does not require the owner to replace those spaces elsewhere on the lot, and the project is not required to correct any existing or newly created nonconformity as a condition of the ministerial building permit.