Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of Santa Clarita (Santa Clarita (its own permits)). Verify your parcel's jurisdiction before filing — different agencies, different rules.
Santa Clarita Valley · LA County (Unincorporated)
ADU permits in Stevenson Ranch
Zip codes:91381
Stevenson Ranch is a master-planned unincorporated community of about 22,000 people in the Santa Clarita Valley (SCV), immediately west of the City of Santa Clarita. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety) under LA County Code Title 22, not through Santa Clarita's building department. The community was master-planned in the early 1990s on former ranch land.
Unincorporated LA County, not LADBS
Stevenson Ranch 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 Stevenson Ranch-specific permit pathway is detailed below.
Stevenson Ranch by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
22,000
2020 Census
Single-family homes
~6,800
LA County Assessor
Median lot size
7,400 sqft
Approximate
ADU permits filed 2025
~61
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 70.
What makes Stevenson Ranch different
Stevenson Ranch is unincorporated despite immediately adjoining Santa Clarita city limits. Permits run through LA County DPW Building & Safety at the Santa Clarita field office via EPIC-LA. Most parcels are inside master-association HOAs that layer architectural review on top of LA County's permit process. Western foothill parcels sit in the Very High Fire Hazard Severity Zone (VHFHSZ) — Chapter 7A construction required.
LA County ADU rules for Stevenson Ranch
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to Stevenson Ranch. 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), Santa Clarita field office Not Santa Clarita city. EPIC-LA portal. |
| Fire-hazard construction | Chapter 7A required on VHFHSZ parcels (western foothills) |
| Local processing time | 60 days from complete submittal (state-mandated) |
Active overlays + extra rules in Stevenson Ranch
LA County overlays + state-level designations that hit a meaningful share of Stevenson Ranch parcels.
Very High Fire Hazard Severity Zone (VHFHSZ)
~35% of parcelsWestern foothill parcels. Chapter 7A construction + defensible space at final.
Master-association HOA architectural review
~85% of parcelsMost parcels in master-association HOAs with architectural review on exterior changes.
Watch-outs specific to Stevenson Ranch
- 01
HOA architectural review is layered on top of LA County permits
Almost every Stevenson Ranch parcel is in a master-association HOA. The HOA's architectural review layers on top of LA County's permit process. Get HOA scoping done before drafting plans.
- 02
Don't file with Santa Clarita city — it's LA County
Stevenson Ranch residents often default to Santa Clarita city for permits, then have to restart with LA County. Verify your parcel's jurisdiction.
- 03
Six Flags Magic Mountain rental-market context
Six Flags Magic Mountain is immediately west of Stevenson Ranch. Short-term rental (STR) ADU economics here are stronger than mid-SCV averages — but most master-association HOAs prohibit STRs. Verify CC&Rs.
Need a person, not a wizard?
Routes that fit Stevenson Ranch
Based on what we know about Stevenson Ranch, these are the lead types that usually make sense here. Pick whichever fits your situation. All free, no obligation.
Complex permit context
Request a Stevenson Ranch permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Stevenson Ranch 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 Stevenson Ranch projects.
Complex permit context
Request a Stevenson Ranch permit referral
Coastal, hillside, historic, fire-zone, or multi-overlay parcels in Stevenson Ranch 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 Stevenson Ranch projects.
Talk to our financing broker
Want someone to walk you through your options?
Our in-house broker has 30+ years in LA mortgage and ADU financing. He'll lay out HELOC, construction-to-perm, and ADU-specific products like Renofi against your situation — free, no obligation.
Talk to our financing broker
Want someone to walk you through your options?
Our in-house broker has 30+ years in LA mortgage and ADU financing. He'll lay out HELOC, construction-to-perm, and ADU-specific products like Renofi against your situation — free, no obligation.
Plans that fit Stevenson Ranch lots
For unincorporated Los Angeles County, the LA County A / B / C pre-approved Accessory Dwelling Unit (ADU) plans are free and usable here. California Department of Housing and Community Development (HCD)-approved prefab also bypasses local plan check entirely.
Amenities + civic services in Stevenson Ranch
Parks, libraries, and the school district that serve the area. Context that matters for renter appeal, family relocation, and long-term resale.
Parks + sports
Stevenson Ranch Community Park
Pico Canyon Road, central Stevenson Ranch
Master-planned community park.
- Baseball
- Playground
- Picnic
- Community Center
Pico Canyon Park
Pico Canyon Road, west Stevenson Ranch
Foothill park with hiking trails. Historic oil-pioneer site (Pico No. 4 well).
California's first commercial oil well (1876)
- Trails
- Picnic
Libraries
Stevenson Ranch Library
LA County Library
Stevenson Ranch Parkway
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
Newhall School District (elementary) + William S. Hart Union High School District
Notable schools in the area
- West Ranch High School (top-performing)
Getting around Stevenson Ranch
Car-dependent master-planned suburban.
Transit + walkability
Bus lines
- Santa Clarita Transit
Walkability
Master-planned walkability within tract centers; car-dependent between tracts.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Stevenson Ranch. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Hollywood Burbank Airport (BUR)
~22 miRegional / domestic
Van Nuys Airport (VNY)
~18 miGeneral aviation
Community + landmarks in Stevenson Ranch
Annual events, landmarks, and the places that anchor the area's identity. Context for renter appeal and long-term resale.
What makes Stevenson Ranch Stevenson Ranch
Historic landmark
Pico No. 4 well
California's first commercial oil well (1876). National Historic Landmark. Located in Pico Canyon Park.
Theme park
Six Flags Magic Mountain (adjacent)
Immediately west of Stevenson Ranch. Regional employment + tourism anchor.
Nearby areas to Stevenson Ranch
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
Castaic →
North-SCV unincorporated community anchored by Castaic Lake recreation area. LA County jurisdiction + VHFHSZ + foothill geotech shape the Accessory Dwelling Unit (ADU) construction context.
LA County unincorporated
Val Verde →
Small SCV unincorporated community with significant Black-American civil-rights heritage (former Eureka Villa resort). LA County jurisdiction shapes the Accessory Dwelling Unit (ADU) calculus.
LA County unincorporated
Agua Dulce →
Rural SCV unincorporated community with multi-acre lots + iconic Vasquez Rocks adjacency. Equestrian zoning + LA County jurisdiction + VHFHSZ coverage shape the Accessory Dwelling Unit (ADU) calculus.
Other permits in Stevenson Ranch
LA County Public Works (Building & Safety) handles ADU, solar, and garage-conversion permits for Stevenson Ranchand the rest of unincorporated LA County. We've broken each out as its own pathway page.
Frequently asked questions about Stevenson Ranch ADUs
›Can I build an ADU in Stevenson Ranch?
Yes. Stevenson Ranch 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 Stevenson Ranch is unincorporated territory rather than a city.
›Why does Stevenson Ranch use LA County rules instead of LA City rules?
Stevenson Ranch 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 Stevenson Ranch 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 Stevenson Ranch?
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. Stevenson Ranch-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 Stevenson Ranch. 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 Stevenson Ranch lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated Stevenson Ranch. 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.
Stevenson Ranch 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