Bolthole Index

Los Angeles County, California

Building permits, zoning and land rules in Duarte, California

Duarte, California adopts its own zoning and requires a Zoning Clearance before the city issues a building permit12. Plan check and inspections run through the Community Development Department at City Hall3. The Los Angeles County Department of Public Health runs the county's septic program; we could not confirm whether it covers addresses inside Duarte, so ask that office before planning a septic system4.

At a glance

Building permit
Required inside Duarte; a Zoning Clearance comes first2
Zoning
City zoning districts R-1 through R-4 and R-MH, set by the Development Code1
Smallest R-1 lot
6,500 square feet in R-1; larger in other districts5
RV parking
Allowed in most single-family and R-2 zones with conditions6
Accessory dwelling
One ADU and one JADU allowed on a single-family residential lot7
Manufactured home
Treated as a single-family dwelling on a permanent foundation8
Septic
Not confirmed for Duarte; ask LA County Public Health4

Who to call

Building permits

City of Duarte Community Development Department, Building & Safety Division

Building plan check, building permit issuance and building inspections inside Duarte city limits

(626) 386-6817

1600 Huntington Drive, Duarte, CA 91010

Zoning

City of Duarte Community Development Department, Planning Division

Zoning questions, the Development Code and planning inquiries inside Duarte city limits

(626) 386-6817

[email protected]

1600 Huntington Drive, Duarte, CA 91010

Septic permits

LA County Department of Public Health, Environmental Health – Onsite Wastewater Treatment Program

County review of septic (onsite wastewater treatment) system plans, soil evaluations and inspections; confirm with this office whether it covers a specific Duarte address

(626) 430-5380

5050 Commerce Drive, Baldwin Park, CA 91706

Contact details are copied from each office’s official page and were checked against it on October 16, 2026.

Off-grid gear

Going off-grid in Duarte means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Duarte, California?

Yes. Inside Duarte city limits, a Zoning Clearance must be obtained before the city issues a new or modified building permit, grading permit or other construction permit for work on a structure2. Other municipal-code and agency permits may also be required before construction or use begins2.

The city does not have an online portal for plan submissions and does not accept submissions by e-mail; plans go to the Community Development Department counter3. Inspections by the building inspector are required for all permits3.

Owner-builders get no special treatment on the permit itself: California's owner-builder rules exempt an owner from contractor licensing under conditions, but owner-builders remain responsible for obtaining building permits and passing inspections9. We could not confirm a Duarte-specific owner-builder rule, so ask the Building & Safety Division3.

Who issues building permits in Duarte, and how do you reach them?

The City of Duarte issues building permits for addresses inside the city, through its Community Development Department at 1600 Huntington Drive; the phone number is (626) 386-68173. Building plan check and inspection services are provided to the city under a contract with Charles Abbott Associates, and the Community Development Director manages that contract3.

For zoning questions before you draw plans, contact the Planning Division, which asks general inquiries to go to [email protected]10. Permits are valid for 180 days3.

The Los Angeles County Public Works and Regional Planning offices serve unincorporated land, not addresses inside Duarte; the county's own page says an address outside its jurisdiction may be handled by another office11. For land outside city limits, see the Los Angeles County page.

Does Duarte have zoning, and what does it mean for lot size, setbacks and RVs?

Duarte has its own zoning. The Development Code sets residential zones R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, R-3, R-4 and R-MH12.

Minimum lot sizes depend on the district: R-1 requires 6,500 square feet5, R-1A requires 7,500 square feet13, R-1B requires 10,000 square feet14, R-1D (the Hillside area) requires 20,000 square feet15, R-1E requires 20,000 square feet16 and R-1F requires 80,000 square feet17.

In R-1 and R-2 zones, a second story must be set back an additional 2.5 feet when the first story sits at the minimum side or rear setback18. In R-3 and R-4, the rear setback grows by 5 feet for each story above the first19.

We could not confirm a general residential height limit, lot-coverage rule or minimum home size for Duarte; ask the Planning Division10.

Can you live in an RV or tiny home in Duarte?

Parking an RV and living in one are different questions. Duarte allows unenclosed RV parking only in the R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2 and R-MH zones, and not in R-3 or R-4 unless the RV is inside a fully enclosed approved structure6. Motor homes may not exceed 40 feet in length or 12 feet in height, and trailers may not exceed 30 feet6.

We could not confirm a Duarte rule that allows living in an RV on a residential lot. California's baseline is that RVs are not intended for occupancy as permanent dwellings, and RV occupancy is generally limited to mobilehome or special occupancy parks unless a local ordinance allows otherwise20. Camping is unlawful at listed locations such as critical infrastructure and within 25 feet of it21.

Duarte's code reviewed here does not address tiny homes as a separate use. Under California's framework, a tiny home on a chassis with axles is treated as an RV and limited to 400 square feet or less, while one on a foundation must meet the building code22. Ask the Planning Division before buying10.

How do septic permits work inside Duarte?

We could not confirm who issues septic permits for addresses inside Duarte city limits, or whether a septic system is allowed there at all. California's septic rules are overseen by the State Water Board and regional boards, and local agencies may run approved programs23.

In Los Angeles County, the Department of Public Health reviews and approves septic systems under its Local Agency Management Program for unincorporated areas and contracted cities24. Whether Duarte is covered is the open question. Call the Onsite Wastewater Treatment Program at (626) 430-5380 and give your street address4.

The county's septic ordinance bars a new septic permit where a public sewer is available within 200 feet of the building, which matters in a dense city like Duarte, but that rule is written for unincorporated land25. Wells are not addressed in the Duarte sources we reviewed; California leaves well permits to local enforcing agencies26.

Can you add an ADU or place a manufactured home in Duarte?

Duarte allows accessory dwelling units on residentially zoned lots. One detached, attached or converted ADU may be built on a single-family residential lot, plus one junior ADU (JADU), and ADU construction requires a building permit and final inspection7. A JADU is at least 150 square feet and at most 500 square feet7.

A manufactured home in Duarte is treated as a single-family dwelling subject to the residential-zone standards8. It must sit on a permanent, continuous exterior masonry or concrete foundation, with at least a 12-inch roof overhang and a 4:12 roof pitch, and flat roofs are prohibited8. The Director may preclude installation of a unit built 10 or more years before the permit application8.

Building a home in Duarte: the steps, in order

  1. Confirm the zoning district and lot standards with the Planning Division at [email protected]10.
  2. Check flood exposure: new development in flood-prone areas must minimize flood damage and provide adequate drainage27.
  3. Obtain the Zoning Clearance that the city requires before it issues a building permit2.
  4. Submit plans at the Community Development Department counter at 1600 Huntington Drive; there is no online portal or e-mail submission3.
  5. Pay fees and receive the permit once plans are approved; permits are valid for 180 days3. We could not confirm a published Duarte fee schedule, so ask the counter.
  6. Schedule building inspections, which are required for all permits3.
  7. Settle septic or sewer questions with the Los Angeles County Department of Public Health4.

Watch-outs

  • Los Angeles County's Title 22 zoning and county building permits apply to unincorporated land, not automatically to incorporated cities such as Duarte28.
  • We could not confirm septic authority, well rules, driveway rules, short-term rental rules or a published permit fee schedule for Duarte; call the Community Development Department at (626) 386-6817 and the county's Onsite Wastewater Treatment Program at (626) 430-538034.
  • Duarte's R-1D Hillside district requires a 20,000 square foot minimum lot, much larger than the 6,500 square feet in R-1155.
  • Property taxes are set at the county level: Los Angeles County's effective property tax rate is 0.7%29.

Sources

  1. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  2. Duarte Development Code § 19.128.020, Applicability (Duarte), quoted and re-checked
  3. City of Duarte Community Development Department, Building & Safety Division (accessduarte.com)
  4. LA County Department of Public Health, Environmental Health – Onsite Wastewater Treatment Program (admin.publichealth.lacounty.gov)
  5. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  6. Duarte Development Code § 19.38.160, Recreational vehicle parking in residential zones (Duarte), quoted and re-checked
  7. Duarte Development Code § 19.60.160, Accessory dwelling units (Duarte), quoted and re-checked
  8. Duarte Development Code § 19.10.080, Manufactured housing (Duarte), quoted and re-checked
  9. Building Officials - Owner-Builder Overview, quoted and re-checked
  10. City of Duarte Community Development Department, Planning Division (accessduarte.com)
  11. Building and Safety - LA County Public Works Permits, quoted and re-checked
  12. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  13. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  14. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  15. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  16. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  17. Duarte Development Code § 19.10.010, Purpose of residential zones (Duarte), quoted and re-checked
  18. Duarte Development Code § 19.10.040, Multi-story setback (Duarte), quoted and re-checked
  19. Duarte Development Code § 19.10.040, Multi-story setback (Duarte), quoted and re-checked
  20. hcd.ca.gov (California statewide rule), quoted and re-checked
  21. Duarte Municipal Code § 15.10.030, Prohibited activities (Duarte), quoted and re-checked
  22. Information Bulletin 2016-01: Tiny Homes (California statewide rule), quoted and re-checked
  23. Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy) (California statewide rule), quoted and re-checked
  24. Local Agency Management Program (LAMP), quoted and re-checked
  25. New Ordinance Adopted - Local Agency Management Program, quoted and re-checked
  26. Well Standards (California statewide rule), quoted and re-checked
  27. Duarte Municipal Code § 16.40.130, Standards for subdivisions or other proposed new development (Duarte), quoted and re-checked
  28. Los Angeles County Code Title 22: Planning and Zoning, quoted and re-checked
  29. Effective property tax rate: Bolthole Index county data

Written October 16, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Duarte

Duarte’s own rules

  • Building permitRequired

    Alteration, construction, modification, moving, or reconstruction of structures inside Duarte city when a building, grading, or other construction permit is required.

    • A Zoning Clearance must be obtained before the City issues the permit.
    • Other municipal-code and agency permits may also be required before construction or use begins.
    “A Zoning Clearance shall be obtained before the City issues a new or modified Building Permit, Grading Permit, or other construction-related permit required for the alteration, construction, modification, moving, or reconstruction of any structure.”
  • Local zoningPresent

    Land inside Duarte city limits; the city adopts and administers residential zoning districts in its Development Code.

    • Residential zones include R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, R-3, R-4, and R-MH.
    “The residential zones are established to implement the Very Low Density (0-3.5 du/ac), Low Density (1-6 du/ac), Medium Density (7-21 du/ac), and High Density (21-28 du/ac) residential land use designations of the General Plan.”
  • Zoning districtsPublished

    Duarte city zoning districts and residential development standards.

    • The residential-zone chapter identifies R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, R-3, R-4, and R-MH.
    “Chapter 19.10 - RESIDENTIAL ZONES (R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, R-3, R-4, R-MH)”
  • Minimum lot sizeSpecified

    R-1 Single-Family Residential Zone inside Duarte city limits.

    • The Development Code states that the R-1 zones provide six single-family residential zones based on required minimum net lot size.

    minimum net lot size: >= 6500 square feet

    “R-1: 6,500 square foot minimum lot size.”
    5 more reviewed findings on this topic
  • SetbacksSpecified

    Second-story residential structures in R-1 and R-2 zones inside Duarte city limits.

    • If the first-story side or rear setback is the minimum required setback, the second story must add 2.5 feet.
    • No additional second-story setback is required if the first story is set back 30 inches or more beyond the minimum.

    additional second-story setback: >= 2.5 feet (No additional setback if first story is at least 30 inches beyond the minimum)

    “In all R-1 and R-2 zones, where the side or rear yard setback for the first story is the minimum required setback for the applicable zone, the second story of any residential structure shall be set back an additional two and one-half feet from the required minimum setback”
    One more reviewed finding on this topic
    • Specified — Multistory structures in R-3 and R-4 zones inside Duarte city limits.
      “For structures with more than one story in the R-3 and R-4 zones, the rear setback shall be increased by five feet for each story or fractional story above the first story.”
  • Living in an RVLimited

    Recreational-vehicle parking and related residential-site use inside Duarte city residential zones.

    • Unenclosed RV parking is allowed only in R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, and R-MH zones.
    • RV parking is not allowed in R-3 or R-4 unless stored within a fully enclosed approved structure.
    • Motor homes may not exceed 40 feet in length and 12 feet in height; trailers may not exceed 30 feet.
    • Parking is restricted to side and rear yards unless the Director approves an alternative front-yard location; screening, paving, operability, licensing, access, and overhang conditions apply.

    maximum motor-home length: <= 40 feet · maximum motor-home height: <= 12 feet · maximum trailer length: <= 30 feet · minimum screening height: >= 6 feet

    “Recreational vehicles, as defined in Article 9 (Definitions) and when not stored within a fully enclosed structure approved for that purpose, are allowed to be parked only in the R-1, R-1A, R-1B, R-1D, R-1E, R-1F, R-2, and R-MH zones, subject to the standards set forth in this Section.”
  • Camping on your landLimited

    Camping inside Duarte city limits at critical infrastructure, nearby entrances, legally unobstructable rights-of-way, wildfire risk areas, and Public Facilities.

    • The prohibition applies to camping, occupying camp facilities, or using camp paraphernalia at the listed locations.
    • The same section separately restricts storage of personal property at listed locations without written owner consent, subject to City Manager provisions.

    restricted distance from critical infrastructure: <= 25 feet

    “It is unlawful and a public nuisance for any person to camp, occupy camp facilities, or use camp paraphernalia at the following locations: (1) Critical infrastructure; (2) Within twenty-five feet of critical infrastructure;”
  • Manufactured homesAllowed (with conditions)

    Manufactured housing inside Duarte residential zones.

    • A manufactured housing unit is treated as a single-family dwelling and must comply with Chapter 19.10 residential development standards.
    • The unit must be installed and maintained on a permanent, continuous exterior masonry or concrete foundation.
    • Architectural standards apply, including a minimum 12-inch roof overhang and minimum 4:12 roof pitch; flat roofs are prohibited.
    • The Director may preclude installation of a unit constructed 10 or more years before the permit application.

    minimum roof overhang: >= 12 inches · minimum roof pitch: >= 4:12 · construction-age threshold for possible prohibition: >= 10 years (Director may preclude installation)

    “A manufactured housing unit shall be considered a single-family dwelling and is subject to the development standards identified in this chapter 19.10 (residential zones).”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units on residentially zoned lots inside Duarte city limits.

    • One detached, attached, or converted ADU may be constructed on a single-family residential lot.
    • One JADU may be constructed on a single-family residential lot zoned to allow residential use.
    • Additional ADUs/JADUs are subject to the multifamily, Government Code, deed-restriction, owner-occupancy, rental-period, and permit conditions in § 19.60.160.
    • ADU/JADU construction requires a building permit and final inspection or certificate-of-occupancy-related approval under the section.

    minimum JADU size: >= 150 square feet (JADU maximum size is 500 square feet)

    “An accessory dwelling unit may be located only on residentially zoned lots.”
  • Building in a floodplainRequired

    Subdivisions and other proposed new development, including manufactured-home parks or subdivisions, in flood-prone areas inside Duarte city limits.

    • Proposals must minimize flood damage.
    • Public utilities and facilities, including sewer, gas, electrical, and water systems, must be located and constructed to minimize or eliminate flood damage.
    • Adequate drainage must be provided to reduce exposure to flood hazards.
    “If a subdivision proposal or other proposed new development, including manufactured home parks or subdivisions, is in a flood-prone area, any such proposals shall be reviewed to assure that: (a) All such proposals are consistent with the need to minimize flood damage within the flood-prone area;”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Duarte or Los Angeles County directly.

  • Owner-builder exemption — Owner-builder exemptions from Duarte construction-permit requirements.
  • Certificate of occupancy — Certificate-of-occupancy requirements for buildings inside Duarte city.
  • Minimum dwelling size — Residential dwelling units inside Duarte city limits.
  • Lot coverage — Residential lots inside Duarte city limits.
  • Building height — Residential buildings inside Duarte city limits.
11 more unanswered
  • Tiny homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Short-term rentals
  • Permit fees

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Duarte publishes no rule on the point, not that none exists. Los Angeles County’s page lists the county offices to call.

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