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Secondary Unit Ordinance & Updates

2019 Secondary Unit Ordinance Changes

Staff is considering zoning code updates to align with new California State Law requirements for Accessory Dwelling Units (ADUs). The table below includes the current regulations and proposed considerations.

Item Current Regulation Proposed Considerations to Align with California State law
Effective Date City Council approval on July 27, 2018, and subsequent updates approved on May 23, 2019, June 25, 2019, and November 19, 2019. Pending City Council approval on December 17, 2019.
Zoning District ADUs allowed in R-1, R-2, and R-M zoning districts, which are comprised of single-family residences, any Planned Development (PD) district (subject to R-1 standards) or where ADUs are not expressly prohibited, and in low density cluster development if it conforms to development standards of the R-1 zoning district, and the development and use standards of the low density cluster permit. ADUs also allowed in existing portions of multifamily and two-family dwelling units, and limited detached units on those parcels, subject to State law regulations; or on a lot consisting of an existing single-family dwelling unit, with a General Plan Landuse/ Transportation designation of Residential Neighborhood, urban Village, Transit Residential, Urban Residential, Downtown, Mixed-use Neighborhood, Mixed-Use Commercial, rural Residential and Residential Neighborhood.
Minimum Lot Size 3,000 square feet No minimum lot size required
Minimum Setbacks from Rear and Side Property Lines 0 feet for 1-story conversions and new construction; 5 feet for second-story ADUs constructed above a garage or accessory structure. No change to existing Single-Family unit setbacks except second story setback for detached units reduced from 5 feet to 4 feet consistent with State requirements; 4 feet minimum rear and side setbacks required for detached ADU in multi-family developments.
Maximum Height Single story – 18 feet maximum; Second story – 24 feet maximum* *Either a two-story ADU or atop a garage or accessory structure or a two-story ADU. No change in height requirements for ADUs on single family properties; 16 feet maximum height for detached ADUs in multifamily developments.
Rear Yard Coverage Area covered by the secondary dwelling, accessory buildings, and accessory structures, except pools, shall not exceed forty percent (40%) of the rear yard. Area shall not exceed forty percent (40%) of the rear yard or up to 800 square feet, whichever is greater.
Detached ADU Location Detached ADU located in the rear yard of the lot of the one-family dwelling or required to meet minimum setback requirements for an accessory building in accordance with Section 20.30.500. Rear yard only, at least 6 feet away from primary dwelling, attached to a detached garage or other existing accessory structure.. No changes except that ADUs that exceed forty percent (40%) of the rear yard must maintain minimum 4 foot side and rear setbacks. One foot of overhang for eaves would be allowed
ADU Size (in sf)
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 600
5,445 - 9,000 700
9,001 - 10,000 800
10,001 - Up 900
Lot Size (sf) ADU Maximum Size (sf)
Greater than 9,000 1,200
Up to 9000 1,000
Number of Bedrooms and Bathrooms Two bedrooms allowed on lots with an area greater than 9,000 square feet, and only one bathroom. Up to two bedrooms and two bathrooms allowed for all units.
Attached ADU Maximum Floor Area May not exceed 50% of the existing or proposed primary dwelling living area May not exceed 50% of the existing or proposed primary dwelling living area, or 800 square feet, whichever is greater.
Design Standards Require visual compatibility with existing primary dwelling. No design standards, except new simplified standards for attached ADU units for historic buildings listed in the Historic Resources Inventory.
Parking requirements An ADU requires 1 space unless the property qualifies for an exemption under State law—see the parking requirements. If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. Parking spaces may be configured on-site per state law. No change in parking requirements for the ADU, except that replacement parking for garages and carports converted to ADUs will not be required.
Junior ADU Not allowed. Allow smaller attached units with a maximum floor area of up to 500 square feet within the existing walls of a single-family dwelling unit provided with an efficiency kitchen, and may share a bathroom with the primary unit. Owner-occupancy and deed restriction will be required for JADU, subject to State law regulations.

2018 Secondary Unit Ordinance Changes

Based on public input and public hearings before the Planning Commission, in mid-2018 the City Council approved updates to Section 20.30 of the Zoning Code to ease requirements for ADUs. The changes are now expressed in Section 20.30.150 of the Zoning Ordinance. The table below reflects the changes.

Item Existing Regulation Regulation Effective July 27, 2018
Zoning District ADUs allowed in R-1, R-2, and PD (subject to R-1 standards) zoning districts, which are comprised of single-family residences. Additionally allow ADUs in R-M zoning districts, and in any Planned Development (PD) district where ADUs are not expressly prohibited. Development standards of the Municipal Code and of planned developments zones apply in all cases.
Minimum Lot Size 5,445 sf 3,000 sf
Minimum Setbacks from Rear and Side Property Lines 0 feet – Conversions 5 feet – New construction 0 feet – 1-story conversions 5 feet – New construction or for ADUs constructed above a garage or accessory structure.
Maximum Height Single story – 18 feet maximum No 2nd-story unit allowed Single story – 18 feet maximum 2nd-story allowed – 22 feet maximum*
*Either an ADU atop a garage or accessory structure or a two-story ADU.
Rear Yard Coverage Not including pools, not more than 40% of the rear yard may be covered. No change
Detached ADU Location Rear yard only, at least 6 feet away from primary dwelling, attached only to a detached garage. Rear yard only, at least 6 feet away from primary dwelling, attached to a detached garage or other existing accessory structure.
ADU Size (in sf)
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 Not allowed
5,445 - 9,000 600
9,001 - 10,000 650
10,001 - Up 800
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 600
5,445 - 9,000 700
9,001 - 10,000 800
10,001 - Up 900
Number of Bedrooms Studio or 1 bedroom Under 800 sf: Studio or 1 bedroom allowed 800 sf and up: 2 bedrooms maximum allowed
Attached ADU Maximum Floor Area May not exceed 50% of the existing primary dwelling living area May not exceed 50% of the existing or proposed primary dwelling living area
Design Standards Match appearance, and match roof form and pitch Require visual compatibility with existing primary dwelling.
Parking requirements Parking configurations in conformance with State law An ADU requires 1 space unless the property qualifies for an exemption under State law—see Parking section of webpage. If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. The homeowner may apply for a reduction of one space of required parking. Parking spaces may be configured on-site per State law.
Reduction in required off-street parking spaces No more than one dwelling occupies the lot. (Section 20.90.220) No more than one dwelling, in conjunction with an ADU , occupies the lot.
Junior ADU Not allowed Removed from consideration; not part of the approved ordinance.
Front yard paving No more than 50% of the front setback may be paved with any impervious surface. (Section 20.30.440) No more than 50% of the front setback may be paved with any impervious or pervious surface.
ADU requirements for lots in Historic Resources Inventory Requires Single-Family House Permit Waive requirement for a Single-Family House Permit for detached ADU or for conversion of existing accessory structure with no exterior alterations.