Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of Lancaster (Lancaster (its own permits)). Verify your parcel's jurisdiction before filing — different agencies, different rules.
Antelope Valley · LA County (Unincorporated)
ADU permits in Hi Vista
Zip codes:93535
Hi Vista is a tiny rural unincorporated community of about 600 people in the far eastern Antelope Valley, east of Lake Los Angeles. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety).
Unincorporated LA County, not LADBS
Hi Vista 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 Hi Vista-specific permit pathway is detailed below.
Hi Vista by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
600
2020 Census
Single-family homes
~240
LA County Assessor
Median lot size
50,000 sqft
Approximate
ADU permits filed 2025
~3
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 3.
What makes Hi Vista different
Hi Vista is a sparsely-populated high-desert community. Most parcels are on septic + private wells. Permits run through LA County DPW Building & Safety at the Lancaster field office.
LA County ADU rules for Hi Vista
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to Hi Vista. State preemption (Gov Code §65852.2) 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), Lancaster field office |
| Local processing time | 60 days from complete submittal (state-mandated) |
Active overlays + extra rules in Hi Vista
LA County overlays + state-level designations that hit a meaningful share of Hi Vista parcels.
Watch-outs specific to Hi Vista
- 01
Septic + well capacity
Most parcels on septic + private wells. Capacity verification + sometimes upgrade required.
Amenities + civic services in Hi Vista
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
Wilsona School District + Antelope Valley Union High School District
Getting around Hi Vista
Car-only rural.
Transit + walkability
Walkability
Not walkable.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Hi Vista. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
General William J. Fox Airfield (WJF, Lancaster)
~26 miGeneral aviation
Nearby areas to Hi Vista
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
Lake Los Angeles →
Rural eastern Antelope Valley unincorporated community. Multi-acre lots + low entry-cost home values + LA County jurisdiction shape Accessory Dwelling Unit (ADU) economics for owner-occupant + family-use builds.
LA County unincorporated
Sun Village →
Small eastern AV unincorporated community with Black-American homesteading heritage. LA County jurisdiction + rural large lots shape the Accessory Dwelling Unit (ADU) calculus.
LA County unincorporated
Littlerock →
Small southeast AV unincorporated community with peach + apple orchard heritage. LA County jurisdiction + large rural lots shape the Accessory Dwelling Unit (ADU) calculus for family-use builds.
Frequently asked questions about Hi Vista ADUs
›Can I build an ADU in Hi Vista?
Yes. Hi Vista allows ADUs under LA County Code Title 22, aligned with California Gov Code §65852.2. Most single-family lots can host one ADU plus one JADU. Permits go through LA County Public Works (Building & Safety), not LADBS, since Hi Vista is unincorporated territory rather than a city.
›Why does Hi Vista use LA County rules instead of LA City rules?
Hi Vista 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 Hi Vista 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 Hi Vista?
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. Hi Vista-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 Hi Vista. 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 Hi Vista lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated Hi Vista. 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.
Hi Vista 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