Pleasant Hill has created a brochure describing its regulations for ADUs.

 

Extract:

Accessory dwelling units are permitted on lots zoned single-family or multifamily and containing an existing or proposed primary dwelling, subject to approval of a zoning permit.

Attached Accessory Dwelling Units must be within or attached to the primary residence and shall not exceed 50% of the existing area of the residence (including the garage), with a maximum allowable floor area of 1,200 square feet and a minimum of 150 square feet.

Detached Accessory Dwelling Units may have a maximum floor area of 1,200 square feet and must have a minimum of 150 square feet.

For accessory dwelling units, one off-street parking space shall be provided per bedroom. However if
the accessory dwelling unit is contained within the existing area of the building or accessory structure,
with no expansion of the area, no additional parking is required. If the accessory dwelling unit is within
an existing garage, replacement parking, for the spaces previously within the garage, is required on the property (replacement parking cannot be in a tandem configuration and is not required to be covered or enclosed).

Units may be exempt from parking requirements if: 1) located within 1⁄2 mile of public transit, or 2) located within an architecturally and historically significant historic district, or 3) part of the existing primary residence or an existing accessory structure, or 4) when on-street parking permits are required but not offered to the accessory dwelling unit, or 5) located within one block of a car share vehicle site.

See full ADU handout

Permit Submittals