Land Use & Permitting

California's New 2020 ADU Laws Summarized

M. Corbin Jones
March 17, 2020

2020 ADU Legislation Highlights

  • Anyone in CA can now build at least an 800 square foot accessory dwelling unit that is at least 16 feet in height and with a 4-foot side and rear yard setbacks.
  • Properties with an ADU do not need to be owner occupied
  • Residential multifamily properties (1-4 units) can now build up to two ADUs as of right. 
  • Cities are required to review, then approve or deny within 60 days

AB 68 - Land Use: Accessory Dwelling Units.

Author: Phil Ting, District 19  

  1. Before this law: a city can adopt a local ordinance that imposes prohibitive requirements for building an ADU, like Lot Coverage or Minimum Setbacks. This can limit people’s ability to fit an ADU on their lot. New with this law: This bill would delete the provision authorizing the imposition of standards on lot coverage and would prohibit an ordinance from imposing requirements on minimum lot size. The bill would revise the requirements for an accessory dwelling unit by providing that the accessory dwelling unit may be attached to, or located within, an attached garage, storage area, or an accessory structure, as defined.
  2. Before this law: A city was required to review, then approve or deny a permit application within 120 days.  New with this law: This bill would instead require a local agency to ministerially approve or deny a permit application for the creation of an accessory dwelling unit or junior accessory dwelling unit within 60 days from the date the local agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot, and would authorize the permitting agency to delay acting on the permit application if the permit application is submitted with a permit application to create a new single-family or multifamily dwelling on the lot, as specified.
  3. Before this law: A city could adopt an ordinance imposing a minimum or maximum size for an ADU.  New with this law: This bill would instead prohibit the imposition of those limitations if they do not permit at least an 800 square foot accessory dwelling unit that is at least 16 feet in height with 4-foot side and rear yard setbacks to be constructed. This bill would additionally prohibit the imposition of limits on lot coverage, floor area ratio, open space, and minimum lot size if they prohibit the construction of an accessory dwelling unit meeting those specifications.
  4. Before this law: A city was required to approve one ADU permit per single-family zoned property, subject to specified conditions and requirements.  New with this law: This bill would instead require ministerial approval of an application for a building permit within a residential or mixed-use zone to create the following: (1) one accessory dwelling unit and one junior accessory dwelling unit per lot with a proposed or existing single-family dwelling if certain requirements are met; (2) a detached, new construction accessory dwelling unit that meets certain requirements and would authorize a local agency to impose specified conditions relating to floor area and height on that unit; (3) multiple accessory dwelling units within the portions of an existing multifamily dwelling structure provided those units meet certain requirements; or (4) not more than two accessory dwelling units that are located on a lot that has an existing multifamily dwelling, but are detached from that multifamily dwelling and are subject to certain height and rear yard and side setback requirements.
  5. Before this law: A city had to submit its adopted local ADU ordinance to the CA Department of Housing and Community Development within 60 days after adoption for review...and comment.  New with this law: This bill would instead authorize the department to submit written findings to a local agency as to whether the local ordinance complies with state law, and would require the local agency to consider the department’s findings and to amend its ordinance to comply with state law or adopt a resolution with specified findings. The bill would require the department to notify the Attorney General that the local agency is in violation of state law if the local agency does not amend its ordinance or adopt a resolution with specified findings.
  6. New with this law: This bill would also prohibit a local agency from issuing a certificate of occupancy for an accessory dwelling unit before issuing a certificate of occupancy for the primary residence.
  7. New with this law: This bill would require a local agency that has not adopted an ordinance for the creation of junior accessory dwelling units to apply the same standards established by this bill for local agencies with ordinances.
  8. New with this law: This bill would make other conforming changes, including revising definitions and changes clarifying that the above-specified provisions regulating accessory dwelling units and junior accessory dwelling units also apply to the creation of accessory dwelling units and junior accessory dwelling units on proposed structures to be constructed.


AB 670 - Common interest developments: ADUs

Author: Laura Friedman, District 43 

  1. Before this law: Common interest developments, commonly known as condominiums, timeshares, and planned developments, could “effectively prohibit or unreasonably restrict the construction or use of an accessory dwelling unit or junior accessory dwelling unit on a lot that is zoned for single-family residential use” (Civ. Code § 4751(a).) New with this law: This bill would make void and unenforceable any covenant, restriction, or condition contained in any deed, contract, security instrument, or other instrument affecting the transfer or sale of any interest in a planned development, and any provision of a governing document, that effectively prohibits or unreasonably restricts the construction or use of an accessory dwelling unit or junior accessory dwelling unit on a lot zoned for single-family residential use that meets the above-described minimum standards established for those units.  However, the bill would permit reasonable restrictions that do not unreasonably increase the cost to construct, effectively prohibit the construction of, or extinguish the ability to otherwise construct, an accessory dwelling unit or junior accessory dwelling unit consistent with those aforementioned minimum standards provisions.


SB 13 - Land Use: Accessory Dwelling Units.

Author: Bob Wieckowski, Senate District 10 

  1. Before this law:  ADUs could be located within, attached to, or detached from an existing single family home or multi family home. New with this law: ADUs may be attached to, or located within, an attached garage, storage area, or other structure, and that it does not exceed a specified amount of total floor area.
  2. Before this law:  Cities could adopt an ordinance that required homeowners to replace parking spaces if a garage, carport, or covered parking is demolished to construct an ADU. With this new law: Local agencies are prohibited from requiring the replacement of parking spaces of a garage, carport, or covered parking is demolished. 
  3. Before this law: Local agencies could impose minimum and maximum unit size limitations on ADUs, so long as an ordinance allowed for an efficiency unit. New with this law: This bill would prohibit a local agency from establishing a minimum square footage requirement for either an attached or detached accessory dwelling unit that prohibits an efficiency unit, as defined. The bill would also prohibit a local agency from establishing a maximum square footage requirement for either an attached or detached accessory dwelling unit that is less than 850 square feet, and 1,000 square feet if the accessory dwelling unit contains more than one bedroom. The bill would also instead prohibit a local agency from establishing any other minimum or maximum size for an accessory dwelling unit, size based upon a percentage of the proposed or existing primary dwelling, or limits on lot coverage, floor area ratio, open space, and minimum lot size for either attached or detached dwelling units that prohibit at least an 800 square foot accessory dwelling unit that is at least 16 feet in height and with a 4-foot side and rear yard setbacks.
  4. Before this law: Cities required either the ADU or the main home to be owner occupied.  New with this law: A local agency cannot impose an owner-occupant requirement, until January 1, 2025. 
  5. Before this law: Cities were required to miniserilly approve or disapprove an ADU application within 120 days after receiving the application. New with this law: The ministerial approval or disapproval period is reduced to 60 days
  6. Before this law: an ADU might have been subject to utility connection fees or capacity charges requiring new or separate utility connections based on the number of fixtures.  New with this law: This bill would prohibit a local agency, special district, or water corporation from imposing any impact fee, as specified, upon the development of an accessory dwelling unit less than 750 square feet, and would require any impact fees to be charged for an accessory dwelling unit of 750 square feet or more to be proportional to the square footage of the primary dwelling unit. 


1.Check out the article https://www.latimes.com/socal/daily-pilot/opinion/story/2020-01-03/commentary-granny-flats-for-the-new-year-the-gift-of-sweeping-new-adu-laws

2. Book a free consultation on www.oviddesigndevelop.com

3. Follow our Instagram https://www.instagram.com/ovid.design/ to see the work we're doing for our clients.

4. Or email me to chat: corbinj@oviddesigndevelop.com