Verified September 30, 2026

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

✓Detached ADU
✓Attached ADU
✓JADU (Junior ADU)
✓Garage Conversion
Units per single-family lot: up to 3 (ADU + JADU + detached ADU)✓ No owner-occupancy required

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

Sewer: Connection to Los Angeles County Sanitation Districts; sewer lateral connection fees apply for new detached ADUs
Fire Sprinklers: Not required unless the primary structure requires them
Parking: No additional parking required

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

Compiled by the ADUByCity Team. How we verify city data.

Disclaimer: Information is compiled from publicly available municipal codes for general informational purposes only. It does not constitute legal, zoning, or construction advice. Regulations change frequently. Always verify with your local planning department. Last verified: September 30, 2026. Verify with City of Whittier Community Development Department: Planning Division

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

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Official Source

City of Whittier: Accessory Dwelling Units

Whittier Municipal Code Section 18.10.020 (Accessory uses, Residential Zones)

Last verified: September 30, 2026

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