City Council Agenda Report
March 18, 2025
TO: Honorable City Council
FROM: Jesus M. Gomez, City Manager
BY: Alex Hamilton, Interim Community Development Director Sophia Tatlyan, Senior Planner
SUBJECT: ACCESSORY DWELLING UNIT UPDATE
Background:
An Accessory Dwelling Unit (ADU) is accessory to a primary residence and provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing primary residential unit. The configuration of an ADU varies as follows:
• Detached: The unit is separated from the primary structure. • Attached: The unit is attached to the primary structure. • Converted Existing Space: Existing floor area (e.g., master bedroom, attached garage, storage area, or similar use, or an accessory structure) on the lot of the primary residence that is converted into an independent living unit.
• Junior Accessory Dwelling Unit (JADU): A specific type of conversion of existing space that is contained entirely within an existing or proposed single-family residence.
Since 2003, the California Legislature has adopted numerous laws governing ADUs and JADU’s to limit local regulations and incentivize the construction of ADUs and JADUs. The increased construction of ADUs is part of the state’s overall strategy to address a statewide housing crisis and to increase market rate and affordable housing unit supply. ADUs are typically smaller than the average home in a community, they tend to be more affordable than other market-rate units, thereby better serving lower income households.
The Norwalk Municipal Code (NMC) was last updated in 2018 to comply with ADU state laws at that time.
The 2018 NMC update included use restrictions, location requirements, and development standards for ADUs, but is mostly out of compliance with current state law. While the ADU
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standards adopted in 2018 have been out of compliance with state laws, staff has been applying the state ADU standards as required. Since 2018, the Planning Division has received 430 ADU applications. Currently, the Planning Division is also working with other departments and divisions for a more united and coordinated reviews of ADUs.
Under the current NMC ADU development standards adopted in 2018, one ADU, ranging from 400 to 720 sq. ft. in size, is permitted on properties developed as single-family residences in the R-1, R-2, R-3, and R-4, and R-H zones. Development standards include minimum lot width, size, and primary dwelling size requirements. Property owners are required to live on the property constructed with an ADU.
Changes to ADU Laws
Since the City’s adoption of the ADU ordinance in 2018, there have been additional state ADU bills passed between 2019 to 2024, which are listed as follows: AB 68, 345, 587, 670, 671, 881, 2221, 2533, and SB 13, 477, 897, 1077 and 1211 (Government Code sections 66310 to 66342).
Some of these bills were part of the 2019 legislative ADU housing package. The most significant provisions of these bills are summarized below:
• ADU application review times.
• Elimination of owner-occupancy restrictions for ADUs. • The sale/conveyance of ADUs.
• Introduction of JADUs, ADUs in multi-family properties, and a statewide exemption ADUs (Exempt ADU) and development standards for these types of ADUs. • Standards for conversion of existing accessory buildings into ADUs. • ADUs required to permitted in zones where residential uses are permitted (including mixed-use zones).
• Prohibition of lot coverage limits and minimum lot size requirements. • Minimum and maximum standards for floor area, setbacks, and height. • Off-street parking requirements and replacement.
Junior Accessory Dwelling Units, ADUs in Multiple-Family properties, and Exempt ADUs Currently, the NMC does not include standards for the development of JADUs, ADUs for Multiple-Family Residential properties, and Exempt ADUs. As part of the updates, development standards for the types of ADUs are necessary to conform to the state ADU bills. As previously mentioned, a JADU is a specific type of conversion of existing space that is contained entirely within an existing or proposed single-family residence.
Listed below are the state required JADU development standards that will be incorporated into the City’s NMC update:
1. Must be contained entirely within a single-family residence.
2. May include separate sanitation facilities or may share sanitation facilities with the existing single-family residence.
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3. Must have independent entrance from primary dwelling.
4. Size: 150 sq. ft. minimum to 500 sq. ft. maximum.
5. Owner occupancy covenant required.
6. May not be sold or conveyed separately.
7. Short term rental prohibited.
ADUs on Properties Developed with Multiple Family Dwellings Currently, the NMC does not have development standards for ADUs on properties developed with multi-family dwellings. For the purposes of state ADU law, a structure with two or more attached dwellings on a single lot is considered a multifamily dwelling structure. Under the state ADU bills, the city is required to allow the following ADU configurations:
1. Attached ADUs, subject to all the following:
• Location. Multiple ADUs within portions of existing multiple-family structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, provided each unit complies with state building standards for dwellings.
• Number. ADUs equal to a maximum of 25 percent of the existing dwelling units, with a minimum of one ADU.
2. Detached ADUs, subject to all the following:
• Location. Within an existing or proposed accessory building. • Number. Existing properties - Up to eight detached ADUs or as many detached ADUs as there are primary units on the lot, whichever is less). Proposed Multi- Family Dwellings. – Two ADUs.
• Setbacks. The minimum interior side yard and rear yard setbacks shall be four feet.
Exempt ADUs
Currently, the NMC does not have provisions for Exempt ADUs. An Exempt ADU is a special classification of ADUs that are exempt from lot coverage, floor area ratio (FAR), open space, and minimum lot size. Exempt ADUs include attached and detached ADUs, JADUs, and ADUs on multi-family properties.
Listed below are the state development standards for Exempt ADUs. Exempt ADUs are applicable for both properties developed as single-family and multiple- family dwellings.
Single-Family Structures
1. One ADU and one JADU per lot with a proposed or existing single-family dwelling if all of the following apply:
• The ADU or JADU is within the proposed space of a single-family dwelling or existing space of a single-family dwelling or accessory structure and may include an expansion City Council March 18, 2025
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of not more than 150 sq. ft. beyond the same physical dimensions as the existing accessory structure. An expansion beyond the physical dimensions of the existing accessory structure shall be limited to accommodating ingress and egress. • The space has exterior access from the proposed or existing single-family dwelling. • The side and rear setbacks are sufficient for fire and safety. • The JADU complies with the requirements of Section 66333–63339.
2. One detached, new construction, ADU that does not exceed four-foot side and rear yard setbacks for a lot with a proposed or existing single-family dwelling. The accessory dwelling unit may be combined with a JADU. A local agency may impose the following conditions on the accessory dwelling unit:
• A total floor area limitation of not more than 800 sq. ft. • A height limitation of 16’.
Multi-Family Structures
Multiple accessory dwelling units within the portions of existing multifamily dwelling structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, if each unit complies with state building standards for dwellings.
1. A local agency shall allow at least one accessory dwelling unit within an existing multifamily dwelling and shall allow up to 25 percent of the existing multifamily dwelling units.
2. Not more than eight 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 four-foot rear yard and side setbacks, provided that number of ADUs does not exceed the number of existing dwelling units on the lot.
Comparison of NMC with State Law
Attachment 1 is a comparison of the existing NMC Section 17.04.210 (Accessory Dwelling Units) and how current state ADU laws would affect the existing development standard and requirements.
Planning Commission Meeting
On October 23, 2024, at a regular Planning Commission meeting, staff presented identical information on ADU laws. Planning Commissioners were supportive of providing increased housing opportunities with the construction of ADUs, but raised concerns with the following:
1. Loss of privacy due to reduced setbacks mandated by the state.
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2. Diminished off street parking due to loss of garage structures and limited ADU parking requirements mandated by the state.
3. Loss of neighborhood architecture.
City Council Meeting
The purpose of this item is to provide detailed information and give Councilmembers background and insight for addressing ADUs and the opportunity to provide input as the ADU Ordinance is drafted. Staff will present the existing NMC regulations pertaining to ADUs (Attachment 2), as well as potential code amendments that are necessary to comply with state law (Attachment 3).
This item is informational only; no decision will be made at this time.
Next Steps
After receiving input from the Planning Commission and City Council, Planning Division staff will draft the ADU Ordinance for consideration at a future public hearing. During this hearing, the Planning Commission will make a recommendation to the City Council. Once the ADU Ordinance is adopted, the city must submit a copy to the California Department of Housing and Community Development (HCD) within 60 days. HCD may then review the ordinance and provide written findings on its compliance with state ADU law.
Fiscal Impact:
N/A
Citizens Advised:
N/A
Strategic Plan 2023 Implementation:
N/A
Recommended Action:
Staff seeks City Council feedback to draft an Accessory Dwelling Unit ordinance with Zoning Code Text amendments to be in full compliance with state regulations.
Attachments:
1. NMC Section 17.04.210 (Accessory Dwelling Units) Comparison to state ADU laws
2. NMC Section 17.04.210 Accessory Dwelling Units
3. State ADU Laws (Government Code Section Government Code Sections 66310 to 66342)