It is not yet known whether San Dimas will keep blocking ADUs and JADUs on lots created or developed under SB 1123. The documents published so far do not show the October 13 vote.
What the city is deciding
The City Council was asked to extend the temporary ban, first adopted 5 to 0 on September 22 as Ordinance 1341, for 10 months and 15 days, with adoption requiring at least four of the five council members. An ADU, or accessory dwelling unit, is a second home on a lot, such as a backyard cottage or garage conversion. A JADU, or junior accessory dwelling unit, is a small unit inside the main house. SB 1123 requires staff to approve qualifying projects with up to 10 new lots or homes in single family zones under fixed rules.
Where and who it affects
The ban covers only lots created or developed under SB 1123. It would prohibit zoning approvals, building permits and other land use approvals for ADUs and JADUs on those parcels. The city’s regular rule allows one ADU and one JADU per lot where single family homes are allowed. Staff had received multiple inquiries, but no formal applications.
What it could mean for your property
For an owner or buyer of an SB 1123 lot, permit eligibility is the immediate issue.
The city says an eligible single family lot could otherwise provide 10 main units, 10 ADUs and 10 JADUs, for 30 units total. The temporary rule blocks the ADUs and JADUs, not the main units under SB 1123.
The city cites traffic safety, parking, fire access, sewer, water and strain on existing infrastructure as reasons for the ban.
Questions to ask before you buy or build
- Was this property created or developed under SB 1123?
- Does the city’s record show a formal SB 1123 application for this property or a nearby site?
- Has the City Council adopted a permanent rule yet, and when does the temporary ban end?
What happens next
Ordinance 1341 is scheduled to expire November 6, 2026, unless the extension was adopted. If adopted, draft Ordinance 1342 would take effect immediately and last 10 months and 15 days, but the documents give no calendar end date. Staff says a permanent code change could take up to three months. That process includes a Planning Commission hearing, City Council introduction and a second reading, with the rule effective 30 days after the second reading.