SANTA MONICA—The Santa Monica City Council on May 22 approved an ordinance to amend the City’s Zoning Ordinance regarding standards for Accessory Dwelling Units (ADUs). According to a press release from the city of Santa Monica, an ADU is a dwelling unit providing complete independent living facilities which is located on a parcel with another, primary single-unit dwelling.

ADUs have been referred to as second dwelling units, in-law units, or granny flats. Independent ADU standards in SMMC Section 9.31.300 have been created separate from the Accessory Building and Structures standards in SMMC Section 9.21.020 to prevent any confusion and conflicts between the standards. Key components of the changes include:

Maximum Allowable Size: The maximum allowable size for ADUs is now 650 square feet (SF) for parcels up to and including 6,000 SF in area or 800 SF for parcels greater than 6,000 SF in area. The Zoning Ordinance previously allowed a maximum size of 650 SF for all ADUs. ADUs must still be clearly subordinate to the main dwelling unit on the parcel in terms of size, location, and appearance.

Second Story Size: There is no limit to the size of a second story of an ADU. However, the second story cannot exceed the area of the first story.

Conversions of Existing Accessory Buildings: Conversions of existing non-garage accessory buildings to ADUs are allowed. The Zoning Ordinance previously did not address this.

ADUs remain excluded from R1 parcel coverage calculations per the R1 Interim Zoning Ordinance that Council adopted on April 10, 2018. The ADU development standards are expected to be revisited as part of the forthcoming effort to review and update the R1 Single-Unit Residential development standards over the next 12-18 months.

A second reading of the ordinance will be heard on Tuesday, June 12. If adopted during the meeting, the ordinance will go into effect on July 12, 2018. More details can be found soon on the Planning and Community Development website at For homeowners with questions email