Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of Hawthorne (Hawthorne (its own permits)). Verify your parcel's jurisdiction before filing, different agencies, different rules.
South Bay · LA County (Unincorporated)
ADU permits in Del Rey Island
Zip codes:90250
Del Rey Island is a small unincorporated 'island' community of about 1,500 people in the South Bay, surrounded by the City of Hawthorne. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety), not Hawthorne city's department. The term 'island' refers to the unincorporated parcel completely enclosed by an incorporated city, a common LA County jurisdictional quirk.
Unincorporated LA County, not LADBS
Del Rey Island 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 Del Rey Island-specific permit pathway is detailed below.
Del Rey Island by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
1,500
2020 Census
Single-family homes
~420
LA County Assessor
Median lot size
5,200 sqft
Approximate
ADU permits filed 2025
~7
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 8.
What makes Del Rey Island different
Del Rey Island is one of LA County's classic 'unincorporated islands', completely surrounded by an incorporated city (Hawthorne) but legally separate. Permits run through LA County DPW Building & Safety. Surrounded by LAX flight paths.
LA County ADU rules for Del Rey Island
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to Del Rey Island. 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 Del Rey Island
LA County overlays + state-level designations that hit a meaningful share of Del Rey Island parcels.
LAX Airport-Influence Area
~100% of parcelsSurrounded by LAX flight paths. Sound-attenuation construction required.
Watch-outs specific to Del Rey Island
- 01
'Island' jurisdiction, surrounded by Hawthorne but LA County
Del Rey Island is completely surrounded by Hawthorne city but is itself unincorporated LA County. Verify jurisdiction at the Assessor parcel lookup before filing.
- 02
LAX flight noise is significant
Sound-attenuation construction (STC-rated windows + insulation) is required.
Need a person, not a wizard?
Routes that fit Del Rey Island
Based on what we know about Del Rey Island, these are the lead types that usually make sense here. Pick whichever fits your situation. All free, no obligation.
Complex permit context
Request a Del Rey Island permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Del Rey Island usually mean a permit expediter pays for itself in saved months. We work with affiliated Los Angeles permit expediters and expeditors (both spellings) who've handled Del Rey Island projects.
Complex permit context
Request a Del Rey Island permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Del Rey Island usually mean a permit expediter pays for itself in saved months. We work with affiliated Los Angeles permit expediters and expeditors (both spellings) who've handled Del Rey Island projects.
Amenities + civic services in Del Rey Island
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
Hawthorne School District + Centinela Valley Union High School District
Getting around Del Rey Island
Bus-served suburban.
Transit + walkability
Bus lines
- Metro 215
- Torrance Transit
Walkability
Moderately walkable along major boulevards.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Del Rey Island. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Los Angeles International (LAX)
~3 miInternational
Directly under LAX flight paths.
Hawthorne Municipal (HHR)
~1 miGeneral aviation
Nearby areas to Del Rey Island
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
Del Aire →
Mid-tier home values, South Bay aerospace + tech employment access, and LAX adjacency drive solid Accessory Dwelling Unit (ADU) rental demand. Direct LAX flight-path coverage means sound-attenuation construction is universal.
LA County unincorporated
Lennox →
Affordable home values plus direct LAX adjacency drive solid Accessory Dwelling Unit (ADU) rental demand from airport + South Bay employment. Sound-attenuation construction is the major local design consideration.
LA County unincorporated
Westmont →
Affordable home values + South Los Angeles cultural identity + airport-adjacent employment access drive long-term Accessory Dwelling Unit (ADU) rental demand.
Frequently asked questions about Del Rey Island ADUs
›Can I build an ADU in Del Rey Island?
Yes. Del Rey Island 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 Del Rey Island is unincorporated territory rather than a city.
›Why does Del Rey Island use LA County rules instead of LA City rules?
Del Rey Island 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 Del Rey Island 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 Del Rey Island?
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. Del Rey Island-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 Del Rey Island. 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 Del Rey Island lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated Del Rey Island. 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.
Del Rey Island 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