Pomona | ADUs and SB 9

Pomona ADUs and SB 9: Section 830.A as Rewritten in 2026, and State Two-Unit Rules

An accessory dwelling unit (ADU) is a second home on a lot with a house or an apartment building, with its own kitchen, bathroom and entrance. A junior ADU is a unit of 500 square feet or less inside a house. Pomona regulates both in Section 830.A of its Zoning and Development Code, which the City Council restated in full with Ordinance No. 4363 on February 2, 2026, to match state laws that took effect January 1, 2026. This page sets out those rules, the places where they differ from state law, and how SB 9 applies in a city whose code says nothing about it. The Pomona overview gives the short version.

The 2026 Ordinance

Pomona rewrote its ADU section three times in two years. Urgency Ordinance No. 4353 and Ordinance No. 4354 amended it in late 2024 and early 2025, and Urgency Ordinance No. 4362 and Ordinance No. 4363 replaced it at the end of 2025 and start of 2026. The Council adopted Ordinance No. 4363 at second reading on February 2, 2026 by a 7 to 0 vote. Its recitals give the reason: "new updates to state ADU law take effect January 1, 2026, and for the City's ADU ordinance to remain valid, it must be amended." The staff report says the ordinance takes effect 30 days after adoption, and that the urgency ordinance "will be null and void upon the effective date" of Ordinance No. 4363.

An ADU that meets Section 830.A must not be "Deemed to exceed the allowable density for the lot," must not count under any rule that limits residential growth, and must not trigger a duty to fix a nonconforming zoning condition on the lot. A nonconforming condition is something built under older rules that would not be allowed today.

Two Types, Both by Building Permit

Section 830.A.4 sorts every ADU into Type 1 or Type 2, and the code titles both "Building Permit Only." Type 1 covers four cases that follow the list in Government Code 66323(a); Type 2 covers every other ADU and adds Pomona's size, yard, coverage and design rules. A Type 1 ADU may go on a lot "in a residential or mixed-use zone," and a Type 2 ADU on a lot "zoned to allow single unit dwelling residential use or multi-unit dwelling residential use."

Source: Pomona Zoning and Development Code Sec. 830.A.4, as restated by Ordinance No. 4363.

On a house lot, Type 1 alone allows an interior ADU, a junior ADU and a limited detached ADU of up to 800 square feet. Section 830.A.4 also says "An existing, Accessory Structure of any size may be converted to an Interior ADU," so a large garage or workshop can become an ADU under Type 1, while "Any proposed expansions greater than the 150 additional square feet limited to accommodating ingress and egress are not permitted" in that case.

On a lot with apartments, Section 830.A.4 allows "No more than two Detached ADUs on a lot that has an existing or proposed multi-unit dwelling." Government Code 66323, as amended effective January 1, 2026, allows "not more than eight detached accessory dwelling units" on a lot with an existing multifamily dwelling, never more than the number of existing units, and two on a lot with a proposed multifamily dwelling. For an existing apartment building with three or more units, the Pomona text is stricter than the statute, and the statute controls.

Size, Height and Yards

Source: Pomona Zoning and Development Code Sec. 830.A.3, 830.A.5.b and 830.A.6.b to 830.A.6.d; the size limits apply to Type 2 ADUs.

The size limits count interior livable space, defined as space "intended for human habitation, including living, sleeping, eating, cooking, or sanitation." One Pomona rule reaches below the floor: "Any crawl space taller than 36 inches must be included in the calculation of the total floor area for an ADU." A crawl space is the low open space under a raised floor. Coverage by all buildings may not exceed the percentage of the zoning district, but Section 830.A.6 adds that "no application of front yard, lot coverage, or open-space requirements may require the ADU to be less than 800 square feet of interior livable space."

Height for an ADU is measured differently from other Pomona buildings. Section 830.A.5 defines it as "the vertical distance measured from the adjoining curb level to the highest point of the structure, exclusive of chimneys and ventilators." The form rules for other buildings measure from average grade. On a lot that sits above the street, the curb rule leaves less height for the ADU, so measure the curb before you draw the roof. Front yards follow the zoning district; side and rear yards are the district rule "or 4 feet, whichever is less," and no yard is required for an existing living area or accessory structure converted in place.

Parking, Design and Occupancy

• Parking. "No parking is required for any ADU." A garage, carport or covered parking structure demolished or converted for an ADU does not have to be replaced. Spaces that are provided must be at least 9 by 18 feet, or 9 by 33 feet for tandem parking, which is two cars parked one behind the other.
• Design. For a Type 2 ADU, exterior materials and colors, "including but not limited to walls, roof, window trim, doors, foundation, exposed rafters, knee braces, and decorative tile, must match the appearance and architectural design of those of the primary dwelling." Manufactured and prefabricated units are allowed if they meet that rule.
• Owner occupancy. "ADUs are not subject to an owner-occupancy requirement." A junior ADU is, unless it has its own bathroom or the property is owned by a government agency, land trust or housing organization.
• Renting and selling. No ADU or junior ADU may be rented for less than 30 days, and neither may be sold separately from the lot except as state law allows. A deed restriction stating these limits must be recorded with the Los Angeles County Recorder before the certificate of occupancy is issued.
• Fire sprinklers. Required only if the main house needs them, and an ADU never triggers sprinklers in the existing house.
• Occupancy order. An ADU gets its certificate of occupancy no earlier than the main house, except where a house was destroyed in an emergency declared by the Governor on or after February 1, 2025 and the ADU is detached.

Deadlines and Appeals

The City "will determine whether an application to create or serve an ADU or JADU is complete" within 15 business days, and must list any missing items. It "must approve or deny an application to create an ADU or JADU within 60 days from the date that the city receives a complete application," or the application is deemed approved, unless the applicant asks for a delay or the ADU is filed with a new house, in which case the City may wait to act on the house first. A denial must list every deficient item and say how to fix it. Appeals of an incomplete finding or a denial go in writing to the City Clerk, and the Planning Commission must give a final written decision within 60 business days. A detached garage torn down for an ADU is reviewed with the ADU, and both permits are issued together.

Older unpermitted ADUs get a path. The City may not deny a permit to legalize an ADU built before January 1, 2018 only because it breaks building standards or the ADU rules, unless a correction is needed to protect health and safety or the building is substandard under the Health and Safety Code.

Fees: Three Pomona Texts, One Statute

Government Code 66311.5 bars "any impact fee upon the development of an accessory dwelling unit that has 750 square feet of interior livable space or less," and says larger ADUs pay fees "proportionately in relation to the square footage of the primary dwelling unit." Pomona states the rule three ways:

• Section 830.A.7 (2026). "No impact fee is required for an ADU that is less than or equal to 749 square feet," and an ADU "750 square feet of interior livable space or larger" is charged proportionately. Its example divides "the floor area of the primary dwelling" by "the floor area of the ADU," which is upside down: it would charge a small ADU more than a house.
• City Code Section 70-72(d). "Accessory dwelling units over 750 square feet shall be charged a proportional amount based on the primary structure on-site."
• FY 2024-25 impact fee report. "ADU Square Feet / Primary Residence Square X Total Impact Fee per unit1 = ADU Impact Fee," with the example of an 800 square foot ADU and a 1,600 square foot house paying 50 percent.

Under the statute, an ADU of exactly 750 square feet pays no impact fee, and a larger one pays its size divided by the house size, as the impact fee report shows. Where Section 830.A.7 differs, the statute controls. Section 830.A.7 also says a separate utility connection and the normal connection fee apply when an ADU is built with a new house, and that an interior ADU converted on a single-family lot needs no new connection or connection fee. The permits and fees page lists the impact fee amounts.

The 2026 section still cites Government Code 65852.2, 65852.22 and 65852.26. Those numbers no longer exist in the Legislature's code table; state ADU law now sits in Chapter 13 of the Government Code, from Section 66314 for ADUs and Section 66333 for junior ADUs. Read the current statutes when you check a right.

ADUs on Historic Property

Section 830.A.9 requires a Major Certificate of Appropriateness, decided by the Historic Preservation Commission, for an ADU on a local landmark, in a designated historic district, or on a California Register property in listed cases. Those cases include "The construction of any new Limited Detached ADU on single-unit lot" and any new attached or detached Type 2 ADU. "Review under the Major Certificate of Appropriateness must be limited to architecture only." The FY 2026-27 fee for a Major Certificate is $1,000. The section is headed "Discretionary Review" and says it applies only to ADUs that do not qualify for ministerial approval, yet it lists Type 1 cases; ask the Planning Division how it reads the two together. See the historic districts page.

SB 9 Two-Unit Projects in Pomona

SB 9 is the state law that lets an owner build two primary homes on a lot in a single-family zone. Government Code 65852.21 says such a project "shall be considered ministerially, without discretionary review or a hearing," decided within 60 days. A city may not use standards that would "physically preclude either of the two units from being at least 800 square feet in floor area," may require side and rear setbacks "of up to four feet," and may require "Offstreet parking of up to one space per unit," with none near a major transit stop or high-quality transit corridor.

The Pomona Zoning and Development Code has no SB 9 section, and the City's website could not be opened for this guide. Three local facts matter:

• The local code may already be easier. In the RND districts the use table permits dwelling units, the parking table requires no spaces for the first 3 homes on a lot, and a Development Plan starts at 4 new homes. A two- or three-home project that fits the form module needs no SB 9 claim.
• Tenants and rent control. SB 9 excludes projects that alter "Housing that has been occupied by a tenant in the last three years" or housing "subject to any form of rent or price control." Pomona's rent stabilization ordinance covers rental units in the city unless an exemption is filed.
• Historic districts. SB 9 excludes "A contributing structure within a historic district" designated by city ordinance. Pomona has six historic districts.

An owner who splits a lot under SB 9 and builds two homes on each new lot loses the right to ADUs there: the statute says a city "shall not be required to permit an accessory dwelling unit or a junior accessory dwelling unit on parcels that use both" authorities. See the SB 9 page and the lot size and subdivisions page.

ADUs and Rent Stabilization

Pomona's Rent Stabilization and Eviction Control Ordinance of 2025 caps yearly rent increases at five percent on covered units. Section 30-574 exempts "Single-family owner-occupied residences, including a residence in which the owner-occupant rents or leases no more than two units or bedrooms, including, but not limited to, an accessory dwelling unit or a junior accessory dwelling unit," and any rental unit with a certificate of occupancy issued after February 1, 1995 or "within the previous 15 years." A new ADU falls under the date exemption, but a landlord "shall file a notice of exemption" with the City, and an unfiled exemption leaves the unit covered.

Where to Go Next

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

Frequently Asked Questions

Official sources (checked October 2026)