California ADU rules · San Diego County
Can I Build an ADU in Lemon Grove?
Yes — you can build an ADU in Lemon Grove. California's statewide ADU law requires every city, including Lemon Grove, 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 ruleup to 2 detached + conversions (>=1 or 25% of units)
Local cap of 2 detached ADUs on multifamily lots, not 4 or 8 as in state default.
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 cap is 1,200 sq ft or 100% of primary dwelling, whichever is less.
Max attached ADU size
Local ruleup to 1,200 sq ft or 100% of primary dwelling, whichever is less; if primary <800 sq ft, ADU up to 800 sq ft allowed
Local rule ties attached ADU max to 100% of primary or 1,200 sq ft, whichever is less.
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 rule16 ft
No local transit/2-story exception; 16 ft is the local cap for detached ADUs.
Setbacks
Side setback
Local rule4 ft
4 ft or the underlying zone, whichever is less.
Rear setback
Local rule4 ft
4 ft or the underlying zone, whichever is less.
Front setback
Local ruleper underlying zone
Front setback must match underlying zone.
Separation from main house
Local ruleNone required
No specific separation required for new detached ADUs.
Parking
Parking required
Local ruleUp to 1 space
1 off-street space per ADU, with state exemptions; JADUs require no additional parking except for garage conversions.
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
Local ruleNot required
No replacement parking required for ADU garage conversions; required for JADUs.
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
Owner-occupancy required for JADUs only.
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
Local ruleBuilding permit
No additional zoning clearance for qualifying ADUs.
Lemon Grove limits multifamily lots to 2 detached ADUs and ties both attached and detached ADU maximum size to 1,200 sq ft or 100% of the primary dwelling, whichever is less. No local height bonus for ADUs near transit.
Frequently asked questions
Can I build an ADU in Lemon Grove?
Yes. California's statewide ADU law requires Lemon Grove 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 Lemon Grove?
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 Lemon Grove?
Side and rear setbacks are limited to 4 ft. per underlying zone.
Is parking required for an ADU in Lemon Grove?
Up to 1 space. 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 Lemon Grove?
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 Lemon Grove?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Lemon Grove Municipal Code § 17.24.060 (Ord. 461 § 1, 2022)
- LGMC § 17.24.060(D)(1)(b)(ii)-(iii)
- LGMC § 17.24.060(D)(1)(v)(B), (d)
- LGMC § 17.24.060(D)(1)(v)(B)
- LGMC § 17.24.060(D)(1)(vi)
- LGMC § 17.24.060(D)(1)(vii)
- LGMC § 17.24.060(D)(1)(viii)
- LGMC § 17.24.060(D)(1)(ix)
- LGMC § 17.24.060(D)(1)(f)-(g)
- LGMC § 17.24.060(D)(1)(f)
- LGMC § 17.24.060(D)(1)(c)
- LGMC § 17.24.060(D)(1)(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 § 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 Lemon Grove'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 Lemon Grove Planning before relying on it.
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