Regulations for Accessory Dwelling Units in Santa Monica

Regulations for Accessory Dwelling Units in Santa Monica

“Accessory dwelling units” or ADUs are becoming an increasingly affordable option for aging parents' ability to stay with their their backyard. A 2021 survey of California’s ADU owners by the UC, Berkeley Center for Community Innovation found that most units are detached. Average square footage is 615 SF and 61% are 1-bedroom.

The primary obstacles toward multigenerational backyard living is local regulations and neighborhood opposition. The California ADU market didn’t take off until legislators passed a state law in 2017 that overrode local zoning restrictions that are uniform in the state. In most circumstances you have the right to build an ADU. 90% of local US ADU laws require re-evaluation. (Source: Marketwatch).

The City of Santa Monica 6th Cycle Housing Element
Join us for a Workshop on ADUs
Thursday, May 26th, 2022 at 6PM 

How to access the Virtual Public Workshop:

          o   Open this link :

o   Download the app if you don’t have it already

o   Enter event ID : edhzygae

  • Via Phone:

o   Dial +1 (415) 466-7000

o   Enter the participant PIN: 1935240 followed by # to confirm. 

Please email [email protected] if you have any questions

Join us for a virtual workshop! To help administer Program 1.G of the 6th cycle Housing Element, the City of Santa Monica has received funding from the Southern California Association of Governments (SCAG) to help accelerate accessory dwelling unit (ADU) production as part of the solution to address the state’s housing crisis. The goal of this grant is to help assess and modernize the City’s ADU permitting processes and policies, as well as build informative best practices and develop a user-friendly ADU handbook for Santa Monica.


May 30, 2018 12:04 PM
SANTA MONICA, Calif. – At its meeting on Tuesday, May 22, the Santa Monica City Council approved an ordinance to amend the City’s Zoning Ordinance regarding standards for Accessory Dwelling Units (ADUs). An ADU is a dwelling unit providing complete independent living facilities that is located on a parcel with another, primary single-unit dwelling. ADUs have also 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 avoid any confusion and conflicts between the standards. Here are the key components of the changes:

  • 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 continue to be excluded from R1 parcel coverage calculations per the R1 Interim Zoning Ordinance that Council adopted on April 10, 2018. The ADU development standards will 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 at that meeting, the ordinance will become effective on July 12, 2018. More information will soon be available on the Planning and Community Development website at If you are a homeowner and have questions, please email [email protected].



Learn instantly if you can have an ADU on your property

Browsing online, I found Symbium Build, a free,one-stop resource for ADUs in California. Check it out for yourself. 

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