California ADU rules · Los Angeles County
Can I Build an ADU in Glendora?
Yes — you can build an ADU in Glendora. California's statewide ADU law requires every city, including Glendora, 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 ruleconversions (>=1 or 25% of units) + up to 2 detached
Local cap of 2 detached ADUs per multifamily lot; state allows up to 8.
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
Local maximum matches state cap; explicitly stated in code.
Max attached ADU size
Local rule1,200 sq ft max
Local maximum for attached ADUs is 1,200 sq ft.
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
Local rule500 sq ft
Plus up to 150 sq ft for ingress/egress, per local code.
Max height
Local rule25 ft
Local maximum is 2 stories, not to exceed 25 ft.
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
Local ruleper base zone (regulatory setback of zoning district)
Front setback must match the base zone's regulatory setback.
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
Local ruleNone
No off-street parking required for ADUs; 1 per unit is recommended but not mandatory.
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
CA state lawOnly for a JADU
No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.
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.
Glendora-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Very High Fire Hazard Severity Zone (VHFHSZ)
ADUs not allowed unless lot is served by a public or private street that meets city standards.
Historic Preservation Overlay Zone (HPOZ) or designated historic properties
ADUs not allowed on lots in HPOZ or on designated historic properties.
Hillside areas
Additional fuel modification and slope stabilization requirements may apply.
Glendora limits detached ADUs on multifamily lots to 2, sets a 25 ft/2-story height cap, and prohibits ADUs in historic zones and certain fire hazard areas. No off-street parking is required for ADUs.
Frequently asked questions
Can I build an ADU in Glendora?
Yes. California's statewide ADU law requires Glendora 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 Glendora?
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 Glendora?
Side and rear setbacks are limited to 4 ft. per base zone (regulatory setback of zoning district).
Is parking required for an ADU in Glendora?
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 Glendora?
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 Glendora?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Glendora Municipal Code § 21.04.040, § 21.15.040; Ord. 2095, 11/12/2025
- GMC § 21.04.040
- 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 § 66315 (owner-occupancy)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated Ord. 2095, 11/12/2025. This is an AI-assisted summary of Glendora'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 Glendora Planning before relying on it.
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