Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of Whittier (Whittier (its own permits)). Verify your parcel's jurisdiction before filing, different agencies, different rules.
Gateway Cities · LA County (Unincorporated)
ADU permits in North Whittier
Zip codes:90601
North Whittier is a small unincorporated community of about 8,000 people in the Gateway Cities region of LA County, north of the City of Whittier. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety).
Unincorporated LA County, not LADBS
North Whittier is unincorporated territory. Building permits go through LA County Public Works (Building & Safety) ↗ under LA County Code Title 22, not the Los Angeles Department of Building and Safety (LADBS). Our address checker pulls real feasibility data for any LA County address; the North Whittier-specific permit pathway is detailed below.
North Whittier by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
8,000
2020 Census
Single-family homes
~2,400
LA County Assessor
Median lot size
6,800 sqft
Approximate
ADU permits filed 2025
~28
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 32.
What makes North Whittier different
North Whittier is functionally distinct from Whittier city. Permits run through LA County DPW Building & Safety via EPIC-LA. Adjacent Whittier Hills foothill parcels face hillside review.
LA County ADU rules for North Whittier
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to North Whittier. State preemption (Gov Code §§ 66310-66342) means the county can't reduce below the state baseline. We note where that applies.
| Max detached ADU size | 1,200 sqft (state default) |
| Max ADU height | 16 ft / 18 ft with second-story setbacks |
| Setbacks | 4 ft side / 4 ft rear (state minimum) |
| Permitting agency | LA County Public Works (Building & Safety) |
| Local processing time | 60 days from complete submittal (state-mandated) |
Active overlays + extra rules in North Whittier
LA County overlays + state-level designations that hit a meaningful share of North Whittier parcels.
Whittier Hills foothill adjacency
~25% of parcelsNorthern parcels face hillside review.
Watch-outs specific to North Whittier
- 01
Don't file with Whittier, it's LA County
North Whittier residents often default to Whittier city for permits, then have to restart with LA County.
Amenities + civic services in North Whittier
Parks, libraries, and the school district that serve the area. Context that matters for renter appeal, family relocation, and long-term resale.
Public schools
School assignments vary by exact address. Performance levels below are from the official California School Dashboard, California's official accountability system uses colored levels (blue highest, red lowest) rather than 1-10 numeric scores.
District
Whittier Union High School District + East Whittier City School District
Getting around North Whittier
Bus-served suburban.
Transit + walkability
Bus lines
- Norwalk Transit
Walkability
Mostly car-dependent.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from North Whittier. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Long Beach Daugherty Field (LGB)
~12 miRegional / domestic
Fullerton Municipal (FUL)
~7 miGeneral aviation
Nearby areas to North Whittier
Other Los Angeles-area pages worth a look. Each one runs different Accessory Dwelling Unit (ADU) rules depending on jurisdiction, we show you what changes when you cross a city or county line.
LA County unincorporated
South Whittier →
Largest unincorporated community in LA County by population. LA County (not Whittier city) jurisdiction shapes the Accessory Dwelling Unit (ADU) permitting path.
LA County unincorporated
West Whittier-Los Nietos →
Mid-size Gateway Cities unincorporated community. LA County jurisdiction + mid-tier home values shape the Accessory Dwelling Unit (ADU) economics.
LA County unincorporated
East La Mirada →
Small Gateway Cities unincorporated community east of La Mirada. LA County (not La Mirada city) jurisdiction shapes the Accessory Dwelling Unit (ADU) permitting path.
Frequently asked questions about North Whittier ADUs
›Can I build an ADU in North Whittier?
Yes. North Whittier allows ADUs under LA County Code Title 22, aligned with California Gov Code §§ 66310-66342. Most single-family lots can host one ADU plus one JADU. Permits go through LA County Public Works (Building & Safety), not LADBS, since North Whittier is unincorporated territory rather than a city.
›Why does North Whittier use LA County rules instead of LA City rules?
North Whittier is unincorporated. It's never been formally incorporated as its own city, so LA County serves as the local government. Building permits, zoning, sheriff, libraries (in many cases), and most other services run through county departments rather than city ones.
›Where do I submit my North Whittier ADU permit?
Online via LA County's EPIC-LA portal, or in-person at the LA County Public Works Building & Safety counter in Alhambra (900 S. Fremont Avenue). The EPIC-LA online portal handles most ADU submittals end-to-end, so you rarely need to visit in person.
›How long does the ADU permit process take in North Whittier?
LA County DPW targets the state-required 60-day plan check for ADUs from a complete submittal. Hillside, VHFHSZ, or environmental-review parcels can extend timelines by 4 to 12 weeks. North Whittier-specific overlays may add additional time. See the watch-outs above.
›Are LA County's pre-approved ADU plans free?
Yes. LA County maintains three pre-approved standard ADU plans (Plans A, B, and C) usable in any unincorporated area, including North Whittier. They're free to use, similar to LADBS's YOU-ADU program. The trade-off is reduced design flexibility, but for a fast, low-cost permit path they're the strongest option.
Ready to see what your North Whittier lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated North Whittier. Start there and we'll surface what applies to your specific lot.
Check your address →Reviewed by Yair Harpaz, Founder, PermitPathLA. California DRE-licensed broker with 30+ years of Los Angeles real estate and mortgage industry experience.
North Whittier ordinance data last reviewed .
See an error or stale rule? corrections@permitpath.la
Primary sources: LA County DPW ADU info · LA County Code Title 22