Everything homeowners need to know about building an accessory dwelling unit in Pomona - size limits, setbacks, permits, and the compliance issues the state found in the city's ordinance before it was corrected.
Last verified: August 2026
6/10 · ADU-friendly
1,200 sq ft*
Max ADU size
18 ft*
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Pomona Zoning and Development Code Section .5809-26 (Accessory Dwelling Units and Junior Accessory Dwelling Units) and California's statewide ADU law (Government Code Sections 66310-66342) for general reference - it is not legal advice. The city's prior ordinance was found noncompliant with state law in 2024 and has since been amended (see ordinance history below). Always confirm current requirements with Pomona Development Services before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached (new construction), lots under 7,200 sq ft
850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms)
18 ft (up to 20 ft to accommodate a matching roof pitch)
Must sit at least 10 ft from the primary residence and 6 ft from other accessory structures
Detached (new construction), lots 7,200 sq ft or larger
1,200 sq ft
18 ft (up to 20 ft to accommodate a matching roof pitch)
Same separation requirements as smaller lots
Attached (addition)
Same size tiers as detached, based on lot size
Up to 25 ft, or the primary dwelling's height, whichever is lower
Front setback follows the underlying zone, but can't be used to block an 800 sq ft ADU
Junior ADU (JADU)
500 sq ft, within existing walls
Within existing primary structure
Owner-occupancy required unless the JADU has its own bathroom, per state law
Allowed zoning districts
Single-family and multifamily residential zoning districts citywide, under Pomona Zoning and Development Code Section .5809-26. State law guarantees at least an 800 sq ft, 16 ft tall ADU regardless of any stricter local limit, and allows a homeowner to combine a converted ADU, a detached new-construction ADU, and a JADU on one lot. Confirm your parcel's zoning with Pomona Development Services.
Additional standards
Setbacks, parking & other rules
Setbacks
4 ft minimum from side and rear property lines for new construction; no setback required for a conversion of legally established existing space
Parking
Not required for an ADU or JADU; where parking is provided voluntarily, standard single (9 ft x 18 ft) or tandem (9 ft x 33 ft) space dimensions apply
Units per lot
On a single-family lot, state law allows combining a converted/interior ADU, a detached new-construction ADU, and a JADU. Multifamily lots can add detached ADUs (up to the number of existing units, capped at 8) plus interior conversions of up to 25% of existing units
Owner-occupancy
Not required for a standard ADU, under statewide AB 976 (effective January 1, 2024). Pomona's own ordinance improperly required it for a period; the state ordered that provision removed (see ordinance history below)
Building code
Must meet the California Residential Code as locally adopted
Rental rules
No enforceable minimum rental term applies to a JADU; a prior 30-day minimum in the city's ordinance was found to violate state JADU law
Ordinance history
How Pomona's ADU rules got here
2017Statewide by-right ADU law takes effect. California Government Code Section 65852.2 begins requiring cities, including Pomona, to approve most ADUs ministerially.
2022Pomona adopts Ordinance No. 4324. The City Council adopted the ordinance as an urgency measure on December 19, 2022, setting the local ADU and JADU standards codified at Section .5809-26.
2024State finds the ordinance noncompliant. An HCD findings letter dated October 29, 2024 identified seven separate ways Ordinance No. 4324 fell short of state ADU and JADU law, including an unlawful owner-occupancy requirement for ADUs created on or after January 1, 2025, a required deed restriction, an improper JADU 30-day rental minimum, a "primary dwelling" definition that excluded multifamily properties, and outdated statutory citations; the city was required to respond by November 27, 2024.
2025Ordinance amended. The city adopted Ordinance No. 4363, amending the Zoning and Development Code's ADU and JADU regulations to correct the issues HCD identified and align with additional state law changes taking effect January 1, 2026.
Worth knowing: Los Angeles County has become one of the country's most active ADU markets, with over 19,000 ADU and JADU permits filed countywide since 2018 and the City of Los Angeles alone permitting 6,626 ADUs in 2024, its second-highest year on record. Pomona's own ordinance took longer than some neighboring cities to reach full state compliance, but the corrected standards now in place are in line with what's required regionally.
Permit process
How Pomona ADU permitting works
1
Pre-application check
Confirm your lot's zoning and any site constraints with Pomona Development Services, (909) 620-2191 or PlanningCounter@pomonaca.gov, before you design.
2
Confirm your property's eligibility
Verify lot size, since it determines whether your detached ADU is capped at 1,000 sq ft or can reach 1,200 sq ft.
3
Prepare your plan set
You'll need a site plan, architectural plans and elevations for the ADU, and structural calculations for the submittal.
4
Submit to Building and Safety
File your application at City Hall, 505 S. Garey Ave., Pomona, CA 91766, or through the city's current online submittal option if available.
5
Ministerial review
The city must approve or deny a complete application within 60 days, with no discretionary hearing; an application not acted on in time is automatically approved.
6
Building permit & inspections
Once your building permit is issued, schedule the standard framing, plumbing, electrical, and final inspections through Certificate of Occupancy.
Fees and timelines are approximate and can change as the city continues to implement its amended ordinance - confirm current figures with Pomona Development Services.
Budgeting
What it costs to build an ADU in Pomona
Garage conversion
Roughly $70,000-$180,000, the least expensive path since the shell already exists
Basement conversion
Uncommon in Pomona's largely slab-built housing stock; where feasible, costs run comparable to or higher than a garage conversion
New detached ADU
Roughly $150,000-$340,000+ for a code-compliant, freestanding unit, depending on size and finishes
Planning & permit fees
Vary by project scope; confirm the current fee schedule with Pomona's Planning Division before budgeting
Impact fees
ADUs of 750 sq ft or less are exempt from most local impact fees under state law; larger ADUs may owe proportional fees
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, finishes, and utility connection needs.
Before you apply
Tips for a smooth approval
Check your lot size before assuming your size cap. Lots under 7,200 sq ft are capped at 850-1,000 sq ft depending on bedroom count; larger lots can reach 1,200 sq ft.
Don't assume you're limited to one ADU. State law allows combining a converted ADU, a detached new-construction ADU, and a JADU on a single-family lot - ask Development Services to confirm your project qualifies for more than one unit.
You should not be asked to sign an owner-occupancy or deed-restriction requirement for a standard ADU. Both were flagged by the state as unlawful in Pomona's prior ordinance; if a current application still references either, ask Development Services to confirm which standards actually apply post-amendment.
Keep new construction at or under 750 sq ft if avoiding impact fees matters to you. Larger units can be charged fees proportional to the primary dwelling's floor area.
Get the current standards in writing. Given the ordinance's recent history, ask Development Services to confirm in writing which size, setback, and unit-count standards apply to your specific submittal.
FAQ
Common questions
Do I need to live on the property to build an ADU in Pomona?
No. California's AB 976 permanently eliminated owner-occupancy requirements for standard ADUs statewide as of January 1, 2024. Pomona's own ordinance improperly required owner-occupancy for a period; the state ordered that removed. A JADU still requires owner-occupancy unless it has its own bathroom.
How many ADUs can I build on one lot in Pomona?
State law allows combining a converted/interior ADU, a detached new-construction ADU, and a JADU on a single-family lot. Multifamily lots can add detached ADUs up to the number of existing units (capped at 8) plus interior conversions of up to 25% of existing units.
Do I need extra parking for an ADU?
No. Parking is not required for an ADU or a JADU in Pomona.
How long does the permit process take?
The city must decide within 60 days of a complete application, with no discretionary hearing. An application not acted on in time is automatically approved.
What's the maximum size for a detached ADU in Pomona?
On a lot under 7,200 sq ft: 850 sq ft for a studio or 1-bedroom, or 1,000 sq ft for 2+ bedrooms. On a lot of 7,200 sq ft or larger: up to 1,200 sq ft. Height is capped at 18 ft (up to 20 ft to match a roof pitch).
How much does an ADU cost to build in Pomona?
Garage conversions tend to run roughly $70,000-$180,000, and new detached units roughly $150,000-$340,000 or more, based on local contractor estimates and regional reporting, not counting permit or impact fees.
Was Pomona's ADU ordinance found to violate state law?
Yes. An HCD findings letter dated October 29, 2024 identified seven ways the city's Ordinance No. 4324 (adopted 2022) did not comply with state ADU and JADU law, including an unlawful owner-occupancy requirement, a required deed restriction, and an improper JADU rental-term minimum. The city subsequently adopted Ordinance No. 4363 in 2025 to correct these issues.
Can I add multiple ADUs if I own a multifamily property in Pomona?
Yes. Under statewide SB 1211 (2024), owners of an existing multifamily property can add detached ADUs up to the number of existing units on the lot (capped at 8), plus interior conversions of up to 25% of existing units.
Is there financial help available for building an ADU in Pomona?
The city has previously offered an ADU/JADU loan program to encourage affordable rental units, though enrollment windows open and close based on available funding. Check current availability with Pomona's Neighborhood Services / Housing Programs division.
