Tracy | ADUs and SB 9

Tracy, California ADUs and SB 9: Ordinance No. 1394, Size, Setbacks, Height, Junior ADUs, Fees and Lot Splits

An accessory dwelling unit (ADU) is a second home on a lot that already has, or will have, a main home. A junior ADU (JADU) is a small unit made inside a house. Tracy rewrote its ADU rules in July 2026 with Ordinance No. 1394. The code published on Municode still shows the 2018 text of the ADU section. This page follows the new ordinance, shows what changed, and marks the points where state law says something different. It then covers SB 9, the state law for two homes and lot splits on single-family lots, which Tracy has not written into its code. The Tracy overview has the summary.

Which Text Applies

Ordinance No. 1394 approves a zoning text amendment "to repeal Article 23, Section 10.08.3180 in its entirety and readopt Article 23, Section 10.08.3180 - Accessory Dwelling Unit." The ordinance "was introduced at a Special Meeting of the Tracy City Council held on the 23rd day of June, 2026, and finally adopted on the 7th day of July, 2026," with five votes in favor and none against. Section 4 says "This Ordinance shall take effect 30 days after its final passage and adoption," which is August 6, 2026 (VanPlex arithmetic: July 7 plus 30 days).

The Supplement History Table of the Municode copy ends at Ordinance No. 1390. The history note under the Municode copy of Section 10.08.3180 ends at "Ord. No. 1254, § 2, 5-1-2018." That older text says "There may be only one accessory dwelling unit on a lot" and "One additional off-street parking space is required per accessory dwelling unit." Both sentences were repealed. A reader who opens the code page before the next supplement will see rules that are no longer in force.

The ordinance gives its own reason. Its recitals say "on July 1, 2025, Tracy City Council adopted the 2023-2031 Housing Element Update," that the state housing department "provided tentative certification on August 11, 2025," and that the Housing Element "requires the Accessory Dwelling Unit section of the municipal code to be updated." The Planning Commission heard the item on May 27, 2026.

Sources: Tracy Municipal Code 10.08.3180 (Supplement 69); Ordinance No. 1394, Exhibit 1.

How Many Units a Lot May Have

• House lots. Subsection (d)(1): "Single Family Dwellings permit all of the following: one new construction detached ADU located on the same lot as the proposed or existing primary dwelling, one ADU attached to, or located within, the proposed or existing primary dwelling, including attached garages, storage areas or similar uses, or an accessory structure and one JADU." The paragraph ends "In addition, a property is permitted as many ADUs as mandated by State law."
• Apartment lots, detached units. "The number of detached ADUs allowed is up to eight units detached from the primary dwellings if the lot is developed or is proposed to be developed with a multifamily dwelling. The number of ADUs shall not exceed the number of primary dwelling units on the lot."
• Apartment lots, conversions. "The number of conversions ADUs allowed is up to 25% of the number of existing multifamily dwelling units within existing multifamily structures." The space must be "not used as livable space, including, but not limited to, storage rooms, boiler rooms, hallways, attics, basements, or garages." Fractions are "rounded down to the next lower whole number of dwelling units, except that at least one ADU shall be allowed."
• What counts as multifamily. The ordinance defines a multifamily dwelling as "a building with two or more attached primary dwellings on a single lot," so a duplex lot uses the apartment rules.
• No minimum lot size. "There shall be no minimum lot area required to establish an ADU or JADU."

Size, Setbacks and Height

• Detached size. A detached unit "shall not exceed 1,200 square feet."
• Attached size. An attached unit "shall not exceed 50% of the total existing or proposed living area of the primary dwelling up to a maximum of 1,200 square feet. However, regardless of the primary dwelling's size, an ADU shall not be limited to less than 800 square feet."
• The 800 square foot minimum. Lot coverage, open space and front setback rules may shrink a unit, but "in no case shall the application of such requirements limit the size of an ADU to less than 800 square feet."
• Conversions. A unit made by converting a building is limited to that building's floor area, "except that an expansion of not more than 150 square feet is permitted to accommodate ingress and egress to the ADU only."
• Side and rear setbacks. "Minimum setbacks of no less than four feet from the side and rear property lines are required for newly constructed ADUs." A converted or rebuilt structure in the same place needs "no additional setback," provided the existing one "is sufficient for fire and safety."
• Front setback. The same as the primary dwelling, "unless this restricts the unit to less than 800 square feet in which case the unit can encroach into the front setback."
• Detached height. "Detached ADUs shall not exceed one story and a height of 16 feet," with three exceptions: 18 feet within one-half mile of "a transit stop or high-quality transit corridor," and "up to 20 feet if necessary to match the roof pitch of the ADU to that of the primary dwelling"; 18 feet on a lot with "an existing or proposed multi-story multifamily dwelling"; and the height of the zone where the unit "conforms to all regulations of the zone."
• Attached height. "Attached ADUs shall not exceed two stories and a height of 25 feet."
• Other standards. Apart from these points, units "shall conform to the development standards applicable to the lot," including any specific plan. The parking, setbacks and height page lists them by zone.

One line of the height rule is hard to read. Item D says the three exceptions "do not apply to units 800 square feet or less in size, however in no case shall an accessory dwelling unit exceed two stories." The ordinance does not say what height then applies to a small unit. Government Code 66321 requires a city to allow 16 feet for any detached ADU and 18 feet near transit or beside a multi-story apartment building, whatever the unit's size. Ask the Planning Division how it reads item D before designing a small unit taller than 16 feet.

Junior ADUs

The 2018 text had no junior ADU. Ordinance No. 1394 defines one as "a dwelling unit of no more than 500 square feet and contained within the primary dwelling unit, including attached garages, with an efficiency kitchen." An efficiency kitchen is "a cooking facility with appliances, a food preparation counter, and storage cabinets of reasonable size."

• Entrance. "JADUs shall have an independent exterior entrance from the primary dwelling but may also include shared access between the units." A unit that shares a bathroom with the house needs "an interior entry to the primary dwelling's main living area."
• Owner on site. "An owner of record of the lot upon which a JADU is located must occupy either the JADU or the remaining portion of the primary single family dwelling as their principal residence." The rule "does not apply if the property is entirely owned by another governmental agency, land trust, or housing organization."
• Deed restriction. Before the building permit, a restriction is recorded with the County Recorder. It says the unit "may not be sold separately from the primary dwelling(s)," fixes its size, and bans short rentals. A deed restriction is a recorded promise that binds later owners of the land.
• Rentals. "JADUs must be rented for a term no shorter than 30 days."
• Utilities. A junior ADU uses the house's water, sewer and other connections, "and no separate utility meters shall be permitted for a JADU."

How an ADU Is Approved

Review is ministerial, which means staff check the plans against fixed rules and use no judgment. Subsection (c) says "Applications for ADUs or JADUs shall be considered ministerially through the building plan check process. The Director, or their designee, shall consider and approve or disapprove a complete application for an ADU or JADU within 60 days from the date the City receives a complete application." The Director is the Director of Community and Economic Development.

• No development review permit. Section 10.08.3930 of the code already exempts "an accessory dwelling unit or residential accessory structure" from the City's design permit.
• With a new house. If the ADU is filed with a new main home, the Director "may delay acting upon the application for the ADU or JADU until the City acts on the application to create the new single-family, two-family, or multifamily dwelling."
• If denied. The Director returns "a complete list of items that are defective or deficient and a description of how the application can be remedied by the applicant" within the 60 days.
• Old problems on the lot. The Director "shall not deny an application for an ADU or JADU due to the presence of nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety and are not affected by the construction of the ADU or JADU."
• Garage demolition. "If an application proposes to demolish a detached garage and replace it with an ADU, the demolition permit shall be reviewed concurrently with the ADU application."
• Unpermitted units. The City may not deny a permit to legalize a unit "constructed before January 1, 2020" because it breaks building standards or the ADU rules, unless a correction is needed under Health and Safety Code Section 17920.3. On application, the City "must delay enforcement against a qualifying substandard ADU for five years."
• Sprinklers. "Fire sprinklers are required in an ADU only if sprinklers are required in the primary residence."
• Growth limit. An ADU needs no residential growth allotment. See the growth management page.

Government Code 66317 adds two deadlines that the ordinance leaves out. The City must say whether an application is complete "not later than 15 business days after the permitting agency received the application," and "If the local agency has not approved or denied the completed application within 60 days, the application shall be deemed approved."

Utilities, Fees, Renting and Selling

• Connections. "An ADU may be served by the same water, sewer, and other utility connections serving the primary dwelling on the property, and the installation of a new or separate utility connection directly between an ADU and a utility is not required." A separate meter is the owner's choice.
• Impact fees. "No impact fee shall be required for an ADU that is less than 750 square feet of gross floor area." A larger unit pays in proportion: "the floor area of the ADU, divided by the floor area of the primary dwelling, times the typical fee amount charged for a new dwelling." An impact fee is a one-time charge on new buildings for public facilities.
• Water capacity fee. Ordinance No. 1404 of September 2026 exempts "Accessory dwelling units unless the accessory dwelling unit was constructed with a new single-family dwelling, or if it has a new or separate utility connection." The permits and fees page covers Title 13.
• Renting. An ADU or JADU "may be rented separate from the primary residence(s) but may not be sold or otherwise conveyed separate from the primary residence(s)."
• No lot split for sale. "A lot shall not be subdivided in any manner which would authorize such separate sale or ownership."
• Kitchens. An ADU kitchen "shall include a kitchen sink, cooking device, refrigeration, food preparation counter, and storage cabinets."

Two other housing types may take the place of an ADU. Section 10.10.212, added in April 2026, says "A tiny home may function as a single-family dwelling as the primary unit or in place of an accessory dwelling unit (ADU)." A tiny home is a unit of at most 400 gross square feet built on a single chassis, and it must be placed on a permanent foundation outside a mobile home park. Section 10.10.222 says the same for a manufactured home. Each is then "subject to all provisions of Article 23, Section 10.08.3180 as they apply to new construction ADUs."

Where Ordinance No. 1394 and State Law Differ

State ADU law sets what a city must allow. Government Code 66316 says that if a city's ADU ordinance "fails to meet the requirements of this article, that ordinance shall be null and void and that agency shall thereafter apply the standards established in this article." On the points below, follow the statute. The ADU law page explains the state rules.

• The 750 square foot line. The ordinance exempts an ADU "that is less than 750 square feet of gross floor area." Government Code 66311.5 bars impact fees on an ADU "that has 750 square feet of interior livable space or less or a junior accessory dwelling unit that has 500 square feet of interior livable space or less." A unit of exactly 750 square feet, and one measured by interior space, come out differently. The statute controls.
• Owner occupancy for junior ADUs. The ordinance requires it for every junior ADU on private land. Government Code 66333, as amended effective January 1, 2026, requires it "If the junior accessory dwelling unit has shared sanitation facilities with the existing structure," and says "Owner-occupancy shall not be required if the junior accessory dwelling unit has separate sanitation facilities."
• Section numbers. The recitals say the City wants to comply with "Government Code section 65852.2 and 65852.22." The Legislature's database, read in October 2026, has no Section 65852.2; the ADU rules are now Sections 66310 to 66342, which the body of the ordinance cites.
• Detached units on apartment lots. The ordinance allows up to eight where a multifamily dwelling exists or is proposed. Government Code 66323 requires eight on a lot with an existing building and "not more than two detached accessory dwelling units" on a lot with a proposed one. Here the City text gives more than the state minimum.
• Rental term. The ordinance says "no shorter than 30 days." Section 66323 says "a term longer than 30 days."
• Completeness and deemed approval. The 15 business day and deemed approval rules of Section 66317 are missing from the ordinance and apply anyway.

SB 9: Two Homes on a Single-Family Lot

SB 9 is the 2021 state law that allows two main homes on a lot in a single-family zone, and a split of that lot into two. A search of Titles 10, 12 and 13 of the Tracy code found no mention of its two sections, Government Code 65852.21 and 66411.7, or of the words "urban lot split." The statute therefore applies directly, and the City may use only the objective standards of the zone.

• Where. The statute applies "within a single-family residential zone." In Tracy the Residential Estate (RE) zone permits "Single-family use," and the Low Density Residential (LDR) zone lists "Single-family dwelling" first among its uses. Since April 2026 LDR also lists "Duplexes, triplexes and fourplexes as part of a larger subdivision." The code does not say which zones the City treats as single-family for SB 9.
• Urban area test. The lot must be in a city that includes part of an urban area named by the Census Bureau. The Bureau's 2020 list includes "Tracy--Mountain House, CA."
• Size. A city may not apply standards that "would physically preclude either of the two units from being at least 800 square feet in floor area."
• Setbacks. "A local agency may require a setback of up to four feet from the side and rear lot lines," and none for a structure rebuilt in the same place.
• Parking. "Offstreet parking of up to one space per unit," and none within one-half mile walking distance of a high-quality transit corridor or major transit stop.
• Deadline. The application is "approved or denied within 60 days from the date the local agency receives a completed application," and is deemed approved after that.
• Tenants. The project may not demolish or alter "Housing that has been occupied by a tenant in the last three years."
• Sprinklers. Section 9.10.060 of the Tracy code requires "An automatic residential fire sprinkler system" in "one- and two-family dwellings."

An urban lot split under Section 66411.7 creates "no more than two new parcels of approximately equal lot area provided that one parcel shall not be smaller than 40 percent of the lot area of the original parcel." Both lots must be "no smaller than 1,200 square feet." The applicant signs an affidavit to "occupy one of the housing units as their principal residence for a minimum of three years." A city "shall not be required to permit more than two units on a parcel created through the exercise of the authority contained within this section," counting ADUs and junior ADUs. The lot size and subdivisions page covers the map steps.

Limits of This Page

Ordinance No. 1394 was read from the PDF that Municode posts in its ordinance bank. The Municode code page for Section 10.08.3180 will change when the next supplement is published. The City's website answered a script with an access denied page, so the City's ADU handout, application form, fee schedule and any pre-approved ADU plans were not read, and no City fee amount is on this page. No letter from the state housing department on Ordinance No. 1394 was found. Whether any Tracy bus or train stop meets the state definitions of a transit stop for the 18-foot height rule and the SB 9 parking rule was not checked. Ask the Planning Division at 333 Civic Center Plaza which text it applies and whether a newer ordinance is in force.

Where to Go Next

Related on VanPlex: the Tracy overview, the California ADU law page and the SB 9 page.

Frequently Asked Questions

Official sources (checked October 2026)