Same zip, different jurisdiction: this page covers LA County Public Works (DPW). The same zip code(s) also cover parts of Covina (Covina (its own permits)). Verify your parcel's jurisdiction before filing, different agencies, different rules.
San Gabriel Valley · LA County (Unincorporated)
ADU permits in Charter Oak
Zip codes:91724
Charter Oak is a small unincorporated community of about 9,300 people in the eastern San Gabriel Valley, between the cities of Covina, Glendora, and San Dimas. It is not a city. Building permits run through Los Angeles County Public Works (Building & Safety).
Unincorporated LA County, not LADBS
Charter Oak 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 Charter Oak-specific permit pathway is detailed below.
Charter Oak by the numbers
Rounded figures from the 2020 US Census, LA County Assessor parcel data, and LA County DPW permit records.
Population
9,300
2020 Census
Single-family homes
~2,700
LA County Assessor
Median lot size
7,400 sqft
Approximate
ADU permits filed 2025
~30
Source: HCD 2025 total (1,278) distributed proportionally across 2024 per-area shares. 2024: 35.
What makes Charter Oak different
Charter Oak is unincorporated despite being tightly integrated with surrounding cities. Permits run through LA County DPW Building & Safety at the Alhambra office.
LA County ADU rules for Charter Oak
Last verified: 2026-04-15
Current LA County rules from Title 22 of the County Code, as applied to Charter Oak. 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), Alhambra office |
| Local processing time | 60 days from complete submittal (state-mandated) |
Active overlays + extra rules in Charter Oak
LA County overlays + state-level designations that hit a meaningful share of Charter Oak parcels.
Watch-outs specific to Charter Oak
- 01
Verify jurisdiction, surrounded by 3 cities
Charter Oak's borders weave between Covina, Glendora, and San Dimas.
Amenities + civic services in Charter Oak
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
Charter Oak Unified School District
Getting around Charter Oak
Bus-served suburban.
Transit + walkability
Bus lines
- Foothill Transit 281
Walkability
Mostly car-dependent.
Nearby airports
Distance + type for each major Los Angeles-area airport reachable from Charter Oak. Useful for travel, commute, and any flight-path noise concerns on specific parcels.
Brackett Field (POC)
~4 miGeneral aviation
Ontario International (ONT)
~10 miInternational
Nearby areas to Charter Oak
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
Vincent →
Central-SGV unincorporated community between Covina + West Covina. LA County jurisdiction + mid-tier home values shape the Accessory Dwelling Unit (ADU) calculus.
LA County unincorporated
Rowland Heights →
Dense Chinese-American + Taiwanese-American unincorporated SGV community. Strong long-term Accessory Dwelling Unit (ADU) rental demand from multigenerational-household culture + premium-Asian-retail commercial anchor.
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.
Frequently asked questions about Charter Oak ADUs
›Can I build an ADU in Charter Oak?
Yes. Charter Oak 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 Charter Oak is unincorporated territory rather than a city.
›Why does Charter Oak use LA County rules instead of LA City rules?
Charter Oak 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 Charter Oak 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 Charter Oak?
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. Charter Oak-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 Charter Oak. 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 Charter Oak lot can do?
Our free address checker pulls real zoning, overlay, and parcel data for any Los Angeles County address, including unincorporated Charter Oak. 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.
Charter Oak 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