In this round of grading, our team reviewed 119 ADU ordinances received by California’s Department of Housing and Community Development (HCD) between December 2019 and February 2021.1 We evaluated the text of the ordinances submitted to HCD, and when information was missing from an ordinance (e.g., for data on fees), we searched the jurisdiction’s website. With some 540 jurisdictions in California, this represents 22% of the state. In some cases, jurisdictions may have modified their ordinances but failed to notify the state. When jurisdictions fail to submit an ADU ordinance to the state, State Law governs their ADU regulations. In these instances, we do not provide a grade.2 

In order to “grade” the ordinances, we created a rubric to score the ADU regulations of each city or county. There are 12 criteria which we assess ordinances against to determine compliance with the 2019 ADU reforms to State Legislation, which became effective on January 1, 2020. In each criterion, jurisdictions generally earn 5 points for compliance with State law, if applicable, and -5 points for non-compliance with CA Code. In certain instances, jurisdictions can receive additional points (up to 15) for best practices and are penalized (deducted points) for programmatic requirements that are not technically illegal but that hinder the ability for residents to construct an ADU. Points within each grading criterion are cumulative. We added the scores for each of the criteria to get a final numerical score for each jurisdiction, which we then used to construct a curve and assign letter grades.

A good grade indicates that jurisdictions are acting in good faith when developing their ADU programs, and generally reflects a regulatory environment friendly to ADU construction. Jurisdictions with high scores do not impose excessive zoning and permitting barriers that could get in the way of ADU construction. A bad grade reflects a regulatory environment that is either non-compliant with State Legislation, or places unnecessary and/or significant barriers in the way of homeowners constructing ADUs. Jurisdictions with low grades generally have burdensome regulatory requirements that restrict ADU construction despite the requirements of the state ADU regulations.

We reviewed the 201 ordinances received by California’s Department of Housing and Community Development (HCD) by September 6, 2019. We evaluated the text of the ordinances submitted to HCD, and when information was missing from an ordinance (e.g., for data on fees), we searched the jurisdiction’s website. With some 540 jurisdictions expected to submit ordinances, this represents 37.2% of the state. In some cases, jurisdictions have modified their ordinances but failed to notify the state; we have evaluated an additional three ordinances in this category, for a total of 204. When jurisdictions fail to submit an ordinance, State law governs their ADU regulations. In these instances, we do not provide a grade.1

In order to “grade” the ordinances, we created a rubric to score the ADU regulations of each city or county. There are 16 equally weighted criteria. Some of these come from the legislation passed in 2016 or 2017, while others come from the 2019 reforms. Three of these offer opportunities to gain extra credit, which include Parking Requirements for ADUs, and Maximum Size for Attached and Detached ADUs.2 Each criterion is valued between 5-20 points, with the exception of Additional Layers of Entitlement or Review, for which jurisdictions may only receive negative points. Points within each grading criteria are cumulative. We added the scores for each of the criteria to get a final numerical score for each jurisdiction, which we then used to construct a curve and assign letter grades.

A good grade reflects a regulatory environment friendly to ADU construction. Jurisdictions with high scores do not impose excessive zoning and permitting barriers that could get in the way of ADU construction. A bad grade reflects a regulatory environment that places unnecessary and/or significant barriers in the way of homeowners constructing ADUs. Jurisdictions with low grades generally have burdensome regulatory requirements that restrict ADU construction despite the requirements of the state ADU ordinance.

1 Presumably, by following state standards, they deserve a good grade; but without the ordinance, we have insufficient evidence to assess their implementation.

2 Jurisdictions received extra credit for Parking Requirements for ADUs if they reduce parking barriers beyond what is required in CA ADU law. For example, not requiring parking for ADUs that are studios (with zero bedrooms) or allowing parking in tandem and/or setbacks. We also gave jurisdictions extra credit for Maximum Size for Attached and Detached ADUs if they did not include the language limiting the maximum size percent increase for either or both criteria. This is another indicator that the jurisdiction is reducing barriers to ADU development.

• • The median ADU ordinance grade in California is a B+, and the mean grade is a B. Not Surprisingly, grades varied across the state.
    
    
  • When compared to our last round of grades, we found that more jurisdictions were in compliance with relevant State Legislation in this round of grading.
    
    
  • The most common instances of non-compliance with State Legislation that we found included jurisdictions imposing subjective design review standards, not complying with the state-mandated setback requirements, and imposing land use regulations that would limit the construction of one, 800 sf ADU that is 16′ tall with 4′ side and rear setbacks.  

• • Across California, jurisdictions tend to score points for allowing generous ADU sizes, as well as including detailed language such as about junior ADUs (JADUs).
    
    
  • Jurisdictions varied in terms of the number of ADUs permitted per lot. Most jurisdictions complied with State Legislation in terms of the number of permissible ADUs, while some did not mention the opportunity to build ADUs on lots with multi-family homes.
    
    
  • ADU impact fee and capacity charge information was often missing from ADU ordinances and public-facing materials online, thus causing jurisdictions to lose points.

• • Jurisdictions received extra credit for best practices including having up-to-date public-facing ADU information online, a dedicated ADU contact person, pre-approved ADU plans, ADU affordability provisions, and amnesty ADU programs.