What could Montebello's 2026 zoning package change?

You may be considering a Montebello property with room for an accessory dwelling unit, planning a major landscape project, or checking what can be built nearby. A four-ordinance zoning package could affect each question. It would update the city’s ADU and junior accessory dwelling unit rules, adopt state water-efficient landscaping standards, and prohibit Artificial Intelligence Data Centers throughout the city.

The package was scheduled for a second reading and adoption on October 28, 2026, but the final action record still needs to be confirmed. This is general information and not legal advice.

What is included in Montebello’s zoning package?

The package contains four ordinances amending Title 17, the zoning title of the Montebello Municipal Code.

Ordinance 2492 updates the definition of an accessory dwelling unit, adds a definition for a junior accessory dwelling unit, and adds a definition of an Artificial Intelligence Data Center. Ordinance 2493 updates Section 17.10.280, titled “Design and development standards for accessory dwelling units,” to make the city’s ADU and JADU standards consistent with state law.

Ordinance 2494 amends Chapter 17.65, Water Conservation in Landscaping Regulations. It would adopt the California Model Water Efficient Landscape Ordinance, commonly called MWELO, in its entirety and as amended from time to time.

Ordinance 2497 adds an AI Data Center classification to Appendix A, the Index of Primary Uses. Its new footnote 65 says, “Artificial Intelligence (AI) Data Centers shall be prohibited in all zoning districts throughout the City.”

These changes appeared together as item 7 at the October 14 public hearing. They returned as item 13 on the October 28 consent calendar with the recommended action, “Waive second reading and adopt.” The amended October 28 agenda corrected clerical errors but kept item 13.

Has the City Council adopted the ordinances?

Adoption remained unconfirmed on November 6, 2026.

The Montebello Planning Commission unanimously approved Resolution No. 17-26 on September 15, 2026, recommending that the City Council adopt all four ordinances. The council introduced them on October 14. The October 28 agenda scheduled the second reading and adoption, but an agenda shows what was scheduled, not the final action.

As of November 6, 2026, Insider had not seen a record that the council adopted the ordinances on October 28, so confirm with the City Clerk (the clerk’s phone printed on the city’s agenda page is (323) 887-1359) before relying on them.

Check the city’s Agendas, Minutes, and Videos page or its CivicClerk agenda portal for the October 28 minutes, an action record, or a later update. Neither the staff report nor the ordinance summary gives an effective date.

For context on another Montebello council matter, see the guide to the Victoria Avenue preferential parking district.

What would change for ADUs and JADUs?

The ordinances would update Montebello’s definitions, review procedures, and design and development standards for ADUs and JADUs.

The staff report describes an ADU as an independent residential dwelling unit on the same lot as an existing or proposed primary residence. It may be attached to the primary dwelling, built as a detached structure, or created by converting existing habitable or non-habitable space.

A JADU is described as a smaller, self-contained residential unit created entirely within the existing or proposed footprint of a single-family residence. Ordinance 2492 adds the JADU definition, while Ordinance 2493 updates the standards in Section 17.10.280.

Appendix A lists ADUs as permitted by right in the R-A, R-1, R-2, R-3, and R-4 zones, subject to Section 17.10.280. That listing does not establish that any particular lot qualifies for an ADU.

The staff report says state ADU law was recodified under Government Code Section 66310 et seq. It does not reproduce the new numeric standards. Do not rely on the report for a setback, height, size, parking, or fee figure. Those details require the adopted text and a property-specific check.

Montebello adopted a 45-day moratorium on new ADUs through Interim Ordinance 2406 on September 26, 2018, then extended it through Ordinance 2415 on August 29, 2019, while studying land use, public services, parking, traffic, and infrastructure.

The California ADU guide provides broader context, but Montebello’s adopted code controls the city review.

How should a buyer check an ADU plan?

A buyer should verify the ordinance status, read the adopted Section 17.10.280, and ask the Planning Division about the specific lot before designing an ADU.

Start by confirming whether Ordinances 2492 and 2493 were adopted and when they became effective. Then obtain a clean version of Section 17.10.280 as adopted. The agenda packet includes Attachment A, but the staff report does not state the controlling numeric rules.

The city’s zone table is only an initial check. Although it shows ADUs as permitted by right in five residential zones, neither the table nor the staff report determines whether a specific parcel can have one. They also give no utility connection requirements.

We spoke with a Montebello owner who had heard that the 2026 zoning package would allow more housing on his lot. He was ready to hire a designer even though the city had not completed the proposal. We reviewed the pending standards with him but based his immediate plans on the rules currently in effect.

What would the AI data center ban cover?

The proposed ban would cover AI Data Centers as defined in Section 17.08.081, not every facility that might be called a data center.

Before this package, Montebello’s Title 17 lacked specific definitions, use classifications, or development standards directly addressing AI Data Centers. On February 11, 2026, the council adopted Urgency Ordinance 2491, an interim measure temporarily prohibiting or restricting their establishment, expansion, or intensification.

Ordinance 2497 would add the permanent classification. Footnote 65 would prohibit AI Data Centers in every zone listed in Appendix A.

The staff report defines these facilities by their operational characteristics and intensity. It cites substantial energy and water consumption, utility infrastructure demands, continuous operations, cooling and mechanical equipment, emergency power generation, noise, emissions, and possible land use compatibility concerns. It also says the facilities may operate continuously, including 24 hours per day and seven days per week.

No proposed data center in Montebello is identified. Neither the staff report nor the ordinance summary connects the ban to any particular property value. For a comparison involving another city, read about Monterey Park’s data center ordinance.

When would the landscaping amendment apply?

The landscaping amendment would apply to certain permitted new and rehabilitated landscape projects meeting the area thresholds stated in the staff report.

For new construction, the report identifies projects with at least 500 square feet of landscape area that require a building or landscape permit, plan check, or design review. For rehabilitated landscapes, it identifies projects with at least 2,500 square feet of landscape area that require one of those reviews.

Ordinance 2494 would adopt the California Department of Water Resources’ MWELO in its entirety, including later amendments. According to the staff report, Government Code Section 65595 requires local agencies to adopt the updated model ordinance or find that a local ordinance is at least as effective.

The report says MWELO does not apply to registered historical sites, certain ecological restoration projects, mined-land reclamation projects, or botanical collections. A buyer planning landscape work should confirm whether the ordinance was adopted and ask the city whether the planned work requires a permit, plan check, or design review.

Staff reported no fiscal impact from the zoning package.

The short version

Montebello’s package would update ADU and JADU rules, adopt state water-efficient landscaping standards, and prohibit AI Data Centers throughout the city’s zoning districts.

As of November 6, 2026, adoption remained unconfirmed. Check the City Clerk’s record and obtain the adopted ordinance text before relying on the package. For an ADU, read Section 17.10.280 as adopted and ask the Planning Division about the specific parcel.

If these zoning questions affect how you’re assessing a Montebello property, start with the home value tool.