Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of La Puente (La Puente (its own permits)) and Industry (City of Industry) (Industry (City of Industry) (its own permits)). Verify your parcel's jurisdiction before filing — different agencies, different rules.
San Gabriel Valley · LA County (Unincorporated)
ADU permits in Rowland Heights
Zip codes:91748
Rowland Heights is an unincorporated community of about 50,000 people in the eastern San Gabriel Valley, bordering Hacienda Heights, La Habra Heights, and Diamond Bar. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety) under LA County Code Title 22. Rowland Heights is one of the densest Chinese-American + Taiwanese-American concentrations in Southern California — Nogales Street and Colima Road host the Pacific Plaza, Diamond Plaza, and Hong Kong Plaza commercial centers anchoring the regional Asian-American retail scene.
Unincorporated LA County, not LADBS
Rowland Heights 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 Rowland Heights-specific permit pathway is detailed below.
Rowland Heights by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
50,000
2020 Census
Single-family homes
~12,500
LA County Assessor
Median lot size
6,500 sqft
Approximate
ADU permits filed 2025
~82
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 95.
What makes Rowland Heights different
Rowland Heights is in unincorporated LA County despite proximity to Diamond Bar (incorporated city) and La Habra Heights. Permits run through LA County DPW Building & Safety at the Alhambra office via EPIC-LA. Multigenerational households are unusually common (per Census ACS data) — extended-family ADU builds dominate the local permit mix more than rental-investment ADUs.
LA County ADU rules for Rowland Heights
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to Rowland Heights. 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), Alhambra office Not LADBS. EPIC-LA portal for online submission. |
| Local processing time | 60 days from complete submittal (state-mandated) |
Active overlays + extra rules in Rowland Heights
LA County overlays + state-level designations that hit a meaningful share of Rowland Heights parcels.
Hillside Management Area (Puente Hills foothills)
~30% of parcelsSouthern + eastern foothill parcels trigger hillside grading review.
Watch-outs specific to Rowland Heights
- 01
Multigenerational-household ADU demand dominates
Rowland Heights has unusually-high multigenerational-household rates. Most ADUs here are built for extended-family use (in-laws, adult children), not rental investments. Floor-plan design priorities differ accordingly.
Plans that fit Rowland Heights 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 Rowland Heights
Parks, libraries, and the school district that serve the area. Context that matters for renter appeal, family relocation, and long-term resale.
Parks + sports
Schabarum Regional Park (north portion)
Colima Road
LA County Regional Park with trails + equestrian center, shared with Hacienda Heights.
- Trails
- Picnic
- Playground
Pathfinder Park
Pathfinder Road
Community park.
- Baseball
- Playground
- Picnic
Libraries
Rowland Heights Library
LA County Library
Nogales Street
Notable bilingual Chinese + English collection.
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
Rowland Unified School District
Notable schools in the area
- Nogales High School
- Rowland High School
Getting around Rowland Heights
Car-dependent suburban with Foothill Transit bus service.
Transit + walkability
Bus lines
- Foothill Transit 482
- Foothill Transit 488
Walkability
Nogales Street + Colima Road commercial corridors walkable; residential car-dependent.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Rowland Heights. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Ontario International (ONT)
~14 miInternational
Los Angeles International (LAX)
~28 miInternational
Brackett Field (POC)
~8 miGeneral aviation
Community + landmarks in Rowland Heights
Annual events, landmarks, and the places that anchor the area's identity. Context for renter appeal and long-term resale.
What makes Rowland Heights Rowland Heights
Walkable Asian retail district
Pacific Plaza + Diamond Plaza commercial corridor
Nogales Street + Colima Road host the regional Asian-American commercial scene — supermarkets, restaurants, services.
Nearby areas to Rowland Heights
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
Hacienda Heights →
Eastern SGV unincorporated community with strong Taiwanese-American cultural roots. Large lots + mid-tier home values + LA County jurisdiction (not LADBS) shape the Accessory Dwelling Unit (ADU) calculus.
LA County unincorporated
Valinda →
Eastern SGV unincorporated community surrounded by West Covina + La Puente + Industry. LA County jurisdiction shapes the Accessory Dwelling Unit (ADU) permitting path.
LA County unincorporated
Vincent →
Central-SGV unincorporated community between Covina + West Covina. LA County jurisdiction + mid-tier home values shape the Accessory Dwelling Unit (ADU) calculus.
Other permits in Rowland Heights
LA County Public Works (Building & Safety) handles ADU, solar, and garage-conversion permits for Rowland Heightsand the rest of unincorporated LA County. We've broken each out as its own pathway page.
Frequently asked questions about Rowland Heights ADUs
›Can I build an ADU in Rowland Heights?
Yes. Rowland Heights 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 Rowland Heights is unincorporated territory rather than a city.
›Why does Rowland Heights use LA County rules instead of LA City rules?
Rowland Heights 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 Rowland Heights 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 Rowland Heights?
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. Rowland Heights-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 Rowland Heights. 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 Rowland Heights lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated Rowland Heights. 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.
Rowland Heights 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