San Joaquin County

Ripon ADU rules

Research summary of local ADU rules on file for Ripon in San Joaquin County. Not a determination for a specific lot.

Last checked October 24, 2026.

City or county ADU page

Ripon rules on file

Local rules recorded in this project for this jurisdiction. Where a city figure on file is stricter than the state baseline on file, both are shown.

Local ADU rules
Ripon's ADU and JADU rules are in Municipal Code Chapter 16.86, amended by Ordinance 937 (2026).
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.010, accessed 2026-10-24.

Review times
All ADUs and JADUs need an ADU or JADU permit and a building permit. The City decides within 15 business days whether an application is complete and reviews a complete application ministerially within 60 days. Incomplete items must be fixed within 30 days or the application expires; completeness appeals are decided within 60 business days.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.030, accessed 2026-10-24.

State-exempt ADUs
“Approved” ministerially: one ADU and one JADU inside a single-family home or existing accessory structure (plus 150 sq ft for access); a new detached ADU up to 800 sq ft with 4 ft side and rear setbacks; converted ADUs in multifamily buildings (at least one, up to 25%); and up to 2 detached ADUs with a proposed multifamily building or up to 8 with an existing one (not more than the existing units).
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.040(A), accessed 2026-10-24.

Size of other ADUs
Non-exempt ADUs: up to 850 sq ft (studio or one bedroom) or 1,000 sq ft (more than one bedroom); other standards cannot reduce an ADU below 800 sq ft.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.050(A), accessed 2026-10-24.

Setbacks
Non-exempt ADUs: front setback as for the main home (subject to the 800 sq ft minimum), 4 ft side and rear, and new detached ADUs at least 6 ft from other buildings.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.050(B), accessed 2026-10-24.

Parking
Non-exempt ADUs: one space per ADU or per bedroom, whichever is less (tandem allowed), with none required near transit (half mile walk), in a historic district, for units in the main home or an existing accessory structure, where on-street permits are not offered, or near car share.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.050(D), accessed 2026-10-24.

Height
Detached ADU: 16 ft, or 18 ft near a major transit stop or high-quality transit corridor (plus 2 ft for roof pitch) or with a multistory multifamily building. Attached ADU: 25 ft or the main home's height limit, whichever is lower. No ADU may exceed two stories.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.060(D), accessed 2026-10-24.

Rentals and sale
ADUs and JADUs may not be rented for fewer than 30 consecutive days or sold separately from the main home except as state law allows.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.060(E)-(F), accessed 2026-10-24.

Fees
No impact fees for JADUs or ADUs under 750 sq ft of interior livable space; larger ADUs pay in proportion, and ADUs over 500 sq ft pay school fees. JADUs pay no impact, connection, capacity or school fees.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), §§ 16.86.060(H), 16.86.070(D), accessed 2026-10-24.

Junior ADUs
Owner occupancy applies only if the JADU shares sanitation facilities with the main home; then a deed restriction is recorded. No added parking for a JADU.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.070, accessed 2026-10-24.

Unpermitted pre-2020 units
The City will not deny a permit to legalize an unpermitted ADU or JADU built before January 1, 2020 for building-code or ADU-rule violations unless a fix is needed under Health and Safety Code § 17920.3. The ADU Amnesty Program includes an inspection, 90 days to make corrections, and no fines for owners who apply voluntarily.
Source: Ripon Municipal Code Ch. 16.86 Accessory Dwelling Units (City of Ripon PDF), § 16.86.080, accessed 2026-10-24.

California state rules on file

The statewide baseline recorded from state law and the HCD ADU Handbook.

Detached size cap described in state law
1,200 sq ft. Recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Side and rear setback cap for a new ADU
4 ft. Recorded in this rules file from Government Code section 66314, which describes a cap on side and rear setbacks for a new ADU.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Setback for a conversion of an existing structure
No additional setback, as recorded in this rules file from Government Code section 66314 for a conversion of an existing structure.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum lot size
A city may not impose a minimum lot size for an ADU, as recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum unit the handbook says cities must allow
At least an 800 sq ft ADU with 4 ft side and rear setbacks. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(3).
Source: HCD ADU Handbook, 66321(b)(3); handbook updated March 2026, accessed 2026-10-16.

Detached height described in the handbook
16 ft, or 18 ft or 20 ft in some cases. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(4).
Source: HCD ADU Handbook, 66321(b)(4); handbook updated March 2026, accessed 2026-10-16.

Permit decision deadline
60 days. Recorded in this rules file from Government Code section 66317(a)(3): the permitting agency must decide on (approve or deny) a completed ADU application within 60 days when an existing single-family or multifamily dwelling is on the lot. Section 66317(a)(1) says the application is considered ministerially, without discretionary review or a hearing.
Source: California Government Code section 66317, 66317(a)(1), (a)(3), accessed 2026-10-17.

Owner-occupancy requirement
None. Recorded in this rules file from Government Code section 66315: a local agency may not impose an owner-occupancy requirement on an ADU. It may require that the property be used for rentals of terms 30 days or longer. The HCD ADU Handbook (updated March 2026) describes the same rule.
Source: California Government Code section 66315, 66315; HCD ADU Handbook updated March 2026, accessed 2026-10-17.

Parking near public transit
No parking standards within one-half mile walking distance of public transit. Recorded in this rules file from Government Code section 66322(a)(1). Section 66322(a) lists several other cases where parking standards may not be imposed.
Source: California Government Code section 66322, 66322(a), accessed 2026-10-17.

Ministerial categories
The HCD ADU Handbook (updated March 2026) states that Government Code section 66323 sets four ministerial categories. This rules file does not restate those four categories.
Source: HCD ADU Handbook, 66323; handbook updated March 2026, accessed 2026-10-16.

Fire Hazard Severity Zones
If your lot is in a Fire Hazard Severity Zone, the CAL FIRE Office of the State Fire Marshal says in Information Bulletin 25-004 (issued March 3, 2025): “Fire Hazard Severity Zones (FHSZs) should not restrict the development of Accessory Dwelling Units (ADUs). However, additional building standards may be necessary, including but not limited to California Fire Code Chapter 49 and California Building Code Chapter 7A.” State ADU law does not itself bar an ADU there. A city or county may still apply its building code, including wildfire-resistant construction (Gov. Code 66314(d)(8)); require side and rear setbacks “sufficient for fire and safety” for a unit converted under 66323(a)(1); and decline parking in setbacks on specific fire and life safety findings (66314(d)(10)(B)). It may also consider public safety when it designates where ADUs may be permitted (66314(a)). Sprinklers can't be required in an ADU or JADU if the primary residence doesn't need them (66314(d)(12), 66323(d)). Some cities and counties still apply their own fire-zone limits. Where this summary has one, it is listed with the local rules. This summary does not look up your lot. Check the CAL FIRE Fire Hazard Severity Zone map viewer linked from the State Fire Marshal's Fire Hazard Severity Zones page: https://experience.arcgis.com/experience/5065c998b4b0462f9ec3c6c226c610a9
Source: CAL FIRE Office of the State Fire Marshal Information Bulletin 25-004, page 4, issued March 3, 2025; Gov. Code 66314, 66323, accessed 2026-10-20.

State baseline on the directory → · State ADU rules on the homepage →

Can I build an ADU in Ripon?

State law sets a baseline for ADUs in Ripon, and the local standards on file are listed on this page. Whether a specific lot can add an ADU depends on zoning, utilities, and other site facts this page does not measure. Confirm with the City of Ripon Planning Department, or run a free address summary.

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