California ADU rules · Los Angeles County
Can I Build an ADU in Pomona?
Yes — you can build an ADU in Pomona. California's statewide ADU law requires every city, including Pomona, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
CA state law1 ADU + 1 JADU
At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).
Units on a multifamily lot
Local ruleConversion ADUs (≥1, up to 25% of existing units) + up to 2 detached
Pomona caps detached ADUs on a multifamily lot at 2 (the state floor allows up to 8), in addition to interior-conversion ADUs of up to 25% of existing units.
Junior ADU (JADU)
CA state lawAllowed
Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).
Size & height
Max detached ADU size
Local rule1,200 sq ft
Scaled by lot size: on lots <7,200 sq ft, 850 sq ft (studio/1-bed) or 1,000 sq ft (2+ beds); on lots ≥7,200 sq ft, 1,200 sq ft. No standard may reduce an allowed ADU below 800 sq ft.
Max attached ADU size
Local ruleAbsolute cap by lot size and bedroom count — 850/1,000 sq ft on lots <7,200 sq ft, 1,200 sq ft on lots ≥7,200 sq ft (no percentage-of-primary formula); never below 800 sq ft
Pomona applies the same absolute size caps to attached and detached ADUs rather than the state '50% of primary' formula.
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
Local rule18 ft
16 ft base for a detached ADU; 18 ft within ½ mi of a major transit stop / high-quality transit corridor (up to 20 ft if needed for roof-pitch alignment) or on a lot with a multifamily dwelling >1 story. Attached ADUs: 25 ft or the primary dwelling's height limit, whichever is less, max 2 stories.
Setbacks
Side setback
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
Front setback
CA state lawNo front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
Local ruleNone
Pomona requires NO parking for any ADU — exceeding the state exemptions. If parking is voluntarily provided it must be on an approved surface, min. 9×18 ft (tandem allowed).
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
CA state lawNot required
When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
Local ruleOnly for a JADU
No owner-occupancy for ADUs. A JADU requires the owner to reside in either the primary dwelling or the JADU (waived where the property is owned by a governmental agency, land trust, or housing organization).
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
CA state lawBuilding permit
Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.
Pomona-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Historic properties & districts
An ADU on a property listed in the California Register of Historical Resources, designated a local landmark, or within a designated historic district requires a Major Certificate of Appropriateness — an architectural review (limited to architecture only) layered onto the otherwise-ministerial ADU path.
Pomona's 2024 Zoning & Development Code scales ADU size by lot (850/1,000 sq ft under 7,200 sq ft; up to 1,200 sq ft at 7,200+) and uses flat square-foot caps instead of the state's 50%-of-primary rule for attached units. It requires zero parking for any ADU and caps detached ADUs on multifamily lots at two. Historic properties are the one place the ministerial path breaks — they need a Major Certificate of Appropriateness for architectural review.
Frequently asked questions
Can I build an ADU in Pomona?
Yes. California's statewide ADU law requires Pomona to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Pomona?
A detached ADU of at least 1,200 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Pomona?
Side and rear setbacks are limited to 4 ft. No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone.
Is parking required for an ADU in Pomona?
None. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Pomona?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Pomona?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Pomona Zoning & Development Code Sec. 830.A (adopted 7/1/2024)
- Pomona Zoning & Dev. Code Sec. 830.A.4.a, .4.b
- Pomona Zoning & Dev. Code Sec. 830.A.6.b
- Pomona Zoning & Dev. Code Sec. 830.A.5.b
- Pomona Zoning & Dev. Code Sec. 830.A.6.f
- Pomona Zoning & Dev. Code Sec. 830.A.5.g
- Pomona Zoning & Dev. Code Sec. 830.A.9.a
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- Cal. Gov. Code § 66314 (local ordinance standards)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated 2026-06-25. This is an AI-assisted summary of Pomona's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Pomona Planning before relying on it.
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