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Union City, CA Accessory Structures: ADU Owner Occupancy (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

JADU owner-occupancy
Required
ADU owner-occupancy
Not required (state law)
JADU max size
500 sq ft
Deed restriction
Must be recorded with City

Summary

Union City exempts ADUs from owner-occupancy under state law, but a junior ADU (JADU) still requires the owner to live in either the main house or the JADU itself.

Owner Occupancy. JADUs shall be subject to owner-occupancy either in the remaining portion of the single-family residence or the newly created JADU. Owner occupancy shall not be required if the owner is another governmental agency, land trust, or housing organization.

E. Deed Restriction. A recordation of a deed restriction, which shall run with the land, shall be filed with the City. The deed restriction shall include:

1. A prohibition of the sale of the JADU separate from the sale of the single-family residence, including a statement that the deed restriction may be enforced against future purchasers; and 2. A restriction on the size and attributes of the JADU that conforms with Government Code Sections 66333 through 66339.

F. Interior Entry. In addition to a separate exterior entrance, JADUs that do not comprise a bathroom shall include an interior entry to the main living area of the single-family residence.

G. Efficiency Kitchen. JADUs shall provide an efficiency kitchen that includes all of the following:

1. A cooking facility with appliances.

2. A food preparation counter and storage cabinets that are of reasonable size in relation to the size of the JADU.

H. Parking. No parking spaces (additional or replacement) shall be required as a condition of permitting a JADU, even when the JADU is converted from an attached garage.

I. New or Separate Unit. JADUs shall not be considered a separate or new dwelling unit for the purposes of:

1.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4940544; v16 updated 2026-06-23).

Full Breakdown

Under Union City Municipal Code § 18.34.040(D), junior accessory dwelling units must have an owner living on-site, in either the remaining single-family residence or the newly created JADU, unless the owner is a governmental agency, land trust, or housing organization. This differs from full-size ADUs, which state law (Gov. Code §§ 66310-66342) exempts from any local owner-occupancy requirement, and Union City's code does not impose one on ADUs. A recorded deed restriction enforcing the JADU rules must be filed with the City.

Violations & Fines

Building or renting a JADU without the recorded owner-occupancy deed restriction is a code violation, prosecutable as a misdemeanor (up to $1,000 fine, 6 months) or an infraction under Chapter 1.16.

Frequently Asked Questions

Do I have to live on-site if I build a JADU in Union City?
Yes. Section 18.34.040(D) requires the owner to occupy either the main house or the JADU, unless the owner is a qualifying public agency, land trust, or housing organization.
Does the owner-occupancy rule apply to a full ADU too?
No. State ADU law overrides local owner-occupancy mandates for ADUs, and Union City's ADU chapter does not impose one: only JADUs carry the requirement.

Sources & Official References

Other rules in Union City

All Union City rules

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ADU Owner Occupancy in Nearby Cities

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