ADU Regulations in Whittier, California
Los Angeles County · CA · Pop. 87,000
Whittier offers preapproved one-story detached ADU plans from a 311 sq ft studio to an 800 sq ft two-bedroom, in Craftsman, Spanish or Traditional styles. The plans include solar panels and a fire sprinkler system, and you must sign a Hold Harmless Agreement before submitting. Older neighborhoods with detached garages are good candidates for conversions.
Max ADU Size
1,200
sq ft detached
Rear Setback
4 ft
Permit Timeline
60 days
Build Cost
$155,000 – $315,000
Local Rules
What's Different in Whittier
- ›Preapproved detached plans: 311, 495, 757 and 800 sq ft
- ›Preapproved plans include solar PV and fire sprinklers and require a geotechnical report
- ›Hold Harmless Agreement required to use city preapproved plans
- ›Detached ADUs up to 16 ft, or 18 ft plus 2 ft near transit
Zoning
Allowed ADU Types
State law requires cities to allow, on a single-family lot, one ADU converted from existing space, one JADU, and one new detached ADU of up to 800 sq ft. Multifamily lots can add up to 8 detached ADUs (not more than the number of existing units) plus conversions of non-livable space for up to 25% of existing units.
Whittier is a historic Southeast Los Angeles County city known for its charming Uptown district and Whittier College. Family-oriented neighborhoods with mature trees and craftsman architecture define much of the residential fabric. ADU regulations comply with California state law, and the city has streamlined its review process.
Source: City of Whittier: Accessory Dwelling Units · Whittier Municipal Code Section 18.10.020 (Accessory uses, Residential Zones)
Dimensions
Size & Setback Requirements
Detached
1,200
sq ft max
JADU
500
sq ft max
Attached
50% of primary home, max 1,200 sq ft
Setbacks
front
Same as primary dwelling per underlying zone
side
4 ft
rear
4 ft
Max height: 16 ft (detached); 18 ft, plus 2 ft for roof pitch, within 1/2 mile of transit
State law floor for detached ADUs: 16 ft; 18 ft within half a mile of major transit (plus 2 ft to match the main roof pitch) or on a lot with a multistory multifamily building.
Lot coverage: Per underlying zone; typically 40–50% in R-1 zones
Whittier's older residential neighborhoods typically feature 6,000–9,000 sq ft lots with detached garages, which are prime candidates for garage conversion ADUs. Historic Uptown Whittier area properties should consult the Planning Division for any design guidelines applicable to their block.
Permitting
Permit Process
Department
City of Whittier Community Development Department: Planning Division
Review Timeline
60 days
Permit Fees
$7,500 – $15,000
Impact Fees
Impact fees waived for ADUs under 750 sq ft; proportional fees apply above that threshold
Required Documents
- ›Site plan (to scale, showing lot dimensions, all structures, setbacks)
- ›Floor plans
- ›Elevations
- ›Title 24 energy compliance (residential)
- ›Structural drawings
Whittier's planning counter processes ADU applications with a focus on ministerial review compliance. The city's over-the-counter pre-application consultation is a useful first step. LA County Sanitation Districts serve Whittier for sewer service.
Infrastructure
Utilities & Requirements
Solar
Required
Parking
Usually none
Separate Meter
Optional
Fire Sprinklers
Only if main home has them
Financials
ADU Costs in Whittier
Typical Build Cost
$155,000 – $315,000
Cost per Sq Ft
$215 – $280
Monthly Rental
$1,600 – $2,500/mo/mo
Property Value Added
Adds $175,000 – $320,000 to property value
Grants & Programs to Check
- ★CalHFA ADU Grant Program (closed since December 2023; watch calhfa.ca.gov for any new funding round)
- ★LA County ADU Finance Program; check with LA County Community Development
Whittier offers stable, long-term rental demand anchored by Whittier College students and staff, Rio Hondo College proximity, and family-oriented residents priced out of closer-in LA neighborhoods. Construction costs are slightly lower than West LA, and the city's historic character supports long-term property value appreciation. Uptown Whittier's dining and retail revival is attracting younger renters to the area.
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State Law
California Rules That Apply in Whittier
Whittier can be more generous than state law but not stricter. These statewide minimums were last reviewed September 30, 2026.
- Units per lot
- Single-family lots can have one ADU converted from existing space, one JADU, and one new detached ADU (up to 800 sq ft). Multifamily lots can add up to 8 detached ADUs (never more than the number of existing units) plus conversions for up to 25% of existing units. Gov. Code §66323; SB 1211 (2024)
- Size
- Cities must allow at least an 800 sq ft ADU with 4 ft side and rear setbacks. Local maximums can be no lower than 850 sq ft (studio or one bedroom) or 1,000 sq ft (two or more bedrooms). JADUs are capped at 500 sq ft of interior livable space. Gov. Code §§66321, 66333
- Height
- Detached ADUs: at least 16 ft; 18 ft within half a mile of major transit (plus 2 ft to match the roof pitch of the main home) or on a lot with a multistory multifamily building. Attached ADUs: 25 ft or the zone height limit, whichever is lower. Gov. Code §66321(b)(4); AB 2221 and SB 897 (2022)
- Setbacks
- Side and rear setbacks for new ADUs can be no more than 4 ft. Conversions of existing legal structures need no extra setback. Front setbacks cannot block an 800 sq ft ADU. Gov. Code §66314(d)(7); AB 2221 (2022)
- Permit timeline
- The city has 15 business days to say whether an application is complete, or it is deemed complete. It must then approve or deny a complete application within 60 days, with no public hearing. Gov. Code §66317; SB 543 (2025)
- Impact fees
- No impact fees on ADUs under 750 sq ft; larger units pay fees proportional to the main home. ADUs and JADUs of 500 sq ft or less are exempt from school impact fees. Gov. Code §66324; SB 543 (2025)
- Owner-occupancy
- Cities cannot require the owner to live on site for an ADU. For a JADU, owner-occupancy can be required only if the JADU shares a bathroom with the main home. JADUs cannot be short-term rentals. AB 976 (2023); AB 1154 (2025)
- Parking
- No parking is required for an ADU within half a mile walk of public transit, in a historic district, or for a conversion, and garage parking lost to an ADU does not have to be replaced. Gov. Code §66322
- Fire sprinklers
- Sprinklers cannot be required in an ADU unless the main home is required to have them. Gov. Code §66314(d)(12)
- Pre-approved plans
- Every city must offer a program for pre-approved detached ADU plans, and plans matching a pre-approved design must be approved or denied within 30 days. AB 1332 (2023); Gov. Code §65852.27
- Selling an ADU
- Cities may choose to let owners sell an ADU separately as a condominium. It is a local opt-in, so check whether your city has adopted it. AB 1033 (2023)
- Unpermitted ADUs
- ADUs built without permits before 2020 can be legalized. Cities cannot deny them for code violations unless the unit is a health and safety hazard, and fees are limited. AB 2533 (2024)
Sources
- City of Whittier: Accessory Dwelling Units (Whittier Municipal Code Section 18.10.020 (Accessory uses, Residential Zones))
- Whittier Municipal Code Section 18.10.020: Accessory uses
- California HCD Accessory Dwelling Unit Handbook
Compiled by the ADUByCity Team. How we verify city data.
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Whittier Quick Facts
- Max size1,200 sq ft
- Rear setback4 ft
- Permit timeline60 days
- Build cost$155,000 – $315,000
- Rental income$1,600 – $2,500/mo/mo
- Owner occupancyNot required
Official Source
City of Whittier: Accessory Dwelling UnitsWhittier Municipal Code Section 18.10.020 (Accessory uses, Residential Zones)
Last verified: September 30, 2026
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