California ADU rules · Shasta County
Can I Build an ADU in Anderson?
Yes — you can build an ADU in Anderson. California's statewide ADU law requires every city, including Anderson, 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
Local rule1 ADU + 1 JADU per legal lot
Units on a multifamily lot
CA state lawConversion ADUs (≥1, up to 25% of units) + up to 8 detached
Conversions of non-livable space (at least 1, or up to 25% of existing units) plus up to 8 detached ADUs on a lot with existing multifamily — never exceeding the number of existing units. JADUs are single-family only.
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 is 1,200 sq ft; minimum is 400 sq ft.
Max attached ADU size
Local rule50% of primary dwelling, not less than 400 sq ft; if 50% is less than 640 sq ft, detached ADU may be up to 640 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
CA state law500 sq ft
Max height
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
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
1 space for studio/1-bedroom, 2 spaces for 2+ bedrooms; may be tandem. State exemptions apply.
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
Local code recites an owner-occupancy requirement, but California Gov. Code § 66315 bars owner-occupancy requirements for ADUs — enforceable for JADUs only. Verify the JADU covenant with the city.
Impact-fee waiver
Local ruleWaived under 750 sq ft
No impact fees for ADUs under 750 sq ft or for units within existing structures without separate utilities.
Permits required
CA state lawBuilding permit
Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.
Anderson-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Fire protection district requirements
ADUs must meet all fire district requirements, including emergency access; sprinklers not required unless for primary residence.
Anderson requires owner-occupancy for either the ADU or the primary dwelling, and sets a local minimum ADU size of 400 sq ft and a maximum of 1,200 sq ft. Parking requirements are higher than state minimums, but state exemptions still apply.
Frequently asked questions
Can I build an ADU in Anderson?
Yes. California's statewide ADU law requires Anderson 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 Anderson?
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 Anderson?
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 Anderson?
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 Anderson?
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 Anderson?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Anderson Municipal Code, Chapter 17.60.030 (Ord. No. 862, § 3, 10-1-2024)
- Anderson Zoning Code § 17.60.030(B)(10)
- Anderson Zoning Code § 17.60.030(B)(4)
- Anderson Zoning Code § 17.60.030(B)(11)
- Anderson Zoning Code § 17.60.030(B)(1)
- Anderson Zoning Code § 17.60.030(B)(8)
- Anderson Zoning Code § 17.60.030(B)(7)
- 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)
Last updated 2026-06-25. This is an AI-assisted summary of Anderson'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 Anderson Planning before relying on it.
Will an ADU work on your Anderson lot?
Ask GoCodebook about your address and get the size, setback, parking and permit rules that actually apply to your parcel — with the exact citation.
Check my parcel free