Bolthole Index

Los Angeles County, California

Zoning, building permits and septic rules in Hawthorne, California

Hawthorne, California requires a building permit for new construction and alterations, issued by the city's own Department of Building and Safety1. Hawthorne also runs its own Title 17 zoning, so Los Angeles County's unincorporated-area zoning does not apply inside city limits23. We could not confirm who permits septic systems inside the city; buildings that connect to the city sewer need a sewer connection permit from the city engineer4.

At a glance

Building permit
Required for new construction and alterations; issued by Hawthorne's Department of Building and Safety15
Building code
California Building Standards Codes with Hawthorne amendments; the city's page names the 2025 code as current65
Zoning
City-run Title 17 zoning with R-1 through R-4 residential districts27
R-1 minimum lot
5,000 sq ft, 50 ft wide, 100 ft deep8
R-1 setbacks
15 ft front (18 ft for a street-facing garage), 5 ft side and rear9
Septic
Not confirmed inside city limits; sewer connection permit from the city engineer where connecting to the city sewer4
RV living / tiny homes
Not confirmed inside city limits; ask the Planning Department10
Mobile homes in R-1
Listed as a permitted use, 12 ft maximum height11

Who to call

Building permits

City of Hawthorne, Department of Building and Safety

Building permits, plan check and construction inspections inside Hawthorne city limits

(310) 349-2990

4455 W. 126th Street, Hawthorne, CA 90250

Online permits →

Zoning

City of Hawthorne, Planning Department

Zoning, development review and planning applications inside Hawthorne city limits

(310) 349-2970

4455 W. 126th Street, Hawthorne, CA 90250

Septic permits

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

Septic (onsite wastewater) plan review for unincorporated Los Angeles County and contracted cities; ask whether it covers a Hawthorne 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 23, 2026.

Off-grid gear

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

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

Hawthorne adopts and applies its own zoning under Title 17 of the municipal code, separate from Los Angeles County's rules for unincorporated land2. The Title 17 index lists residential districts R-1 through R-4, commercial and industrial districts, and open space and horticultural zones7. The Planning Department oversees zoning compliance for private development in the city10.

The main single-family district is R-1 Low-Density Residential8. In R-1, a single-family detached dwelling needs a lot of at least 5,000 square feet, 50 feet wide and 100 feet deep8. R-1 setbacks are 15 feet in front (18 feet when the garage faces the street) and 5 feet on the sides and rear, with the rear setback matching the front on through lots9. Lot coverage is capped at 50%12, and height is capped at 22 feet, or 12 feet on lots under 40 feet wide and under 5,000 square feet13.

Mobile homes are a permitted use in R-1, subject to the same lot standards and a 12-foot height limit11. Check the parcel's district on the city zoning map before assuming these numbers apply.

Do you need a building permit in Hawthorne, and who issues it?

Hawthorne requires building permits for new construction and alterations inside city limits, administered by the city's Department of Building and Safety1. Fences not over 6 feet high are exempt1. Starting work without a required permit can trigger a special investigation and an investigation fee on top of permit fees1.

Los Angeles County Public Works issues building permits only for unincorporated properties, and says another office may handle properties outside its jurisdiction14. Inside Hawthorne, that office is the city's own Building and Safety Department, which handles record keeping, plan check and inspections5.

Hawthorne's code adopts the 2022 California Building Standards Codes with local amendments6. The city's Building and Safety page now names the 2025 California Building Standards Code as current5, and the state says the 2025 code applies to permit applications filed on or after January 1, 202615. Ask the department which edition applies to your application. A certificate of occupancy is not issued until all required work and conditions are met16.

Who is the Hawthorne building department, and how do you reach them?

Hawthorne Building and Safety is at 4455 W. 126th Street, Hawthorne, CA 90250, and the phone is (310) 349-29905. Applications and inspections run through the city's online self-service portal listed with the office. Hawthorne Planning handles zoning questions at the same address, phone (310) 349-297010.

Applications are treated as abandoned 180 days after filing unless pursued in good faith or a permit has been issued; the building official can grant extensions of up to 90 days each, to no more than two years from submittal17. We could not confirm Hawthorne's building permit fee schedule or the full submittal checklist, so ask Building and Safety for both before you budget.

Los Angeles County offices, such as County Public Works and Regional Planning, serve unincorporated land; they are not the right counter for a lot inside Hawthorne3.

How do septic permits work inside Hawthorne?

We could not confirm who issues septic permits, or whether septic systems are allowed at all, inside Hawthorne city limits. Hawthorne's municipal code requires a sewer connection permit from the city engineer, plus the established fees, before anyone connects to the public sewer4. Erecting or altering a building also requires compliance with the city's sewer article first4. In a dense city like this, new buildings will most likely connect to the sewer rather than use a septic system.

Los Angeles County Public Health reviews septic plans for unincorporated areas and contracted cities under its Local Agency Management Program18. We did not confirm whether Hawthorne is one of the contracted cities. Call the Onsite Wastewater Treatment Program at (626) 430-538019 and Hawthorne Building and Safety at (310) 349-29905 before you plan anything other than a sewer connection. Private well permits inside the city also remain unconfirmed.

Can you live in an RV or tiny home on your lot in Hawthorne?

We could not confirm Hawthorne's rules on living in an RV, on tiny homes, or on camping on a residential lot; ask the Planning Department at (310) 349-2970 before parking or placing anything10. The R-1 use table does not list RVs8.

Do not borrow the county's answer. Los Angeles County generally does not allow living in an RV or trailer for any length of time in unincorporated areas, outside narrow exceptions20. That rule covers unincorporated land only, not lots inside Hawthorne.

For tiny homes, California's housing department says a tiny home on a chassis with axles and 400 square feet or less of floor area is treated as an RV, camping cabin or park trailer, while one on a foundation must meet the California Building Standards Code or factory-built housing standards, with local agencies enforcing both21. Whether Hawthorne's zoning allows either on a given lot is what to confirm with Planning.

Building a home in Hawthorne: the steps, in order

  1. Find the parcel's zoning district and confirm lot size, setbacks, coverage and height with the Planning Department108.
  2. If the lot is being divided, note that Hawthorne regulates subdivisions under Title 16 and has a separate chapter for urban lot splits and two-unit developments22.
  3. Ask Building and Safety which code edition and fee schedule apply, then submit plans and apply for the building permit5.
  4. Arrange a sewer connection permit with the city engineer before connecting to the public sewer4.
  5. Schedule inspections through the city's online portal5.
  6. Get the certificate of occupancy once all required work and conditions are complete16.

California has a statewide owner-builder exemption from contractor licensing, but owner-builders remain responsible for obtaining building permits and passing inspections23. We could not confirm any Hawthorne-specific owner-builder rule.

What stays with Los Angeles County, and what to check before you buy in Hawthorne?

Land outside Hawthorne's city limits is a different jurisdiction. For unincorporated land, see the Los Angeles County page, because county permits and zoning rules apply only there24.

Before buying inside Hawthorne, check the parcel's zoning district, whether the lot meets the district's minimum size, and how sewer service reaches it4. If you plan to rent a unit short term, Hawthorne requires a city short-term rental permit25. We could not confirm Hawthorne's rules on driveways and curb cuts, floodplain development or agricultural uses.

Property taxes are set at the county level: Los Angeles County's effective property tax rate is 0.7%26.

Watch-outs

  • Hawthorne's Title 17 zoning chapters were renumbered by an ordinance dated 6/23/2026, so the R-1 chapter now appears as Chapter 17.20a (formerly 17.14); older links and guides may cite the old numbers2.
  • Hawthorne's code lists the 2022 California Building Standards Codes, while the city's Building and Safety page names the 2025 code as current; confirm the edition with Building and Safety before drawing plans56.
  • We could not confirm Hawthorne's building permit fees, septic rules, RV or tiny-home rules, or well rules; call Building and Safety at (310) 349-2990 or Planning at (310) 349-2970510.
  • Los Angeles County's unincorporated-area building, zoning, RV and septic rules do not automatically apply inside Hawthorne3.

Sources

  1. Chapter 15.04 California Building Standards Codes, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  2. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  3. Los Angeles County Code Title 22: Planning and Zoning, quoted and re-checked
  4. Chapter 13.56 Sewer Connections, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  5. City of Hawthorne, Department of Building and Safety (cityofhawthorne.org)
  6. Chapter 15.04 California Building Standards Codes, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  7. Title 17 Zoning, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  8. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  9. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  10. City of Hawthorne, Planning Department (cityofhawthorne.org)
  11. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  12. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  13. Chapter 17.20a R-1 Zone, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  14. Building and Safety - LA County Public Works Permits, quoted and re-checked
  15. Approved Building Standards (California statewide rule), quoted and re-checked
  16. Chapter 15.75 Enforcement, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  17. Chapter 15.04 California Building Standards Codes, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  18. Local Agency Management Program (LAMP), quoted and re-checked
  19. LA County Department of Public Health, Environmental Health – Onsite Wastewater Treatment Program (admin.publichealth.lacounty.gov)
  20. Common Zoning Violations - LA County Planning, quoted and re-checked
  21. Information Bulletin 2016-01 (MH, FBH, SHL, MP/SOP, RT, OL) — Revised: Tiny Homes, quoted and re-checked
  22. City of Hawthorne, CA Code of Ordinances table of contents (eCode360) (Hawthorne), quoted and re-checked
  23. Building Officials - Owner-Builder Overview, quoted and re-checked
  24. Los Angeles County Code Title 22: Planning and Zoning, quoted and re-checked
  25. Chapter 17.24e Short-Term Rental Permits, City of Hawthorne, CA (eCode360) (Hawthorne), quoted and re-checked
  26. Effective property tax rate: Bolthole Index county data

Written October 23, 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 Hawthorne

Hawthorne’s own rules

  • Building permitRequired

    New construction and alterations inside Hawthorne city limits, administered by the city's building official (Department of Building and Safety).

    • Work without a required permit triggers an investigation fee in addition to permit fees (§ 15.04.060, amending CBC 109.4).
    • Fences not over 6 feet high are exempt from permit (§ 15.04.040).
    “whenever any work for which a permit is required by this code has been commenced without first obtaining said permit, a special investigation may be required before a permit may be issued for such work.”
  • Building code adoptedAdopted (with conditions)

    Construction inside Hawthorne city limits.

    • Adopts the 2022 California Building Standards Codes, amended by city ordinance (Ord. 2239, 2023), with local amendments in each Title 15 chapter.
    • Section 15.04.020 provides that the most recently adopted California state code and the Hawthorne Municipal Code take precedence.
    “§ 15.04.010 adoption of the 2022 california building standards codes.”
  • Certificate of occupancyRequired

    New construction and changes of use inside Hawthorne city limits.

    • Certificate of occupancy not issued until required work and conditions, including bonding, are satisfied (§ 15.75.010).
    “a certificate of occupancy shall not be issued until all work required by the building official and all other conditions imposed by a department head, commission, committee or other authority have been completed or satisfactorily met, including, but not limited to, bonding.”
  • Local zoningPresent (with conditions)

    Land inside Hawthorne city limits; the city's own Title 17 zoning ordinance applies.

    • Title 17 was reorganized and renumbered by Ord. 2263 (6/23/2026); the R-1 chapter now appears as Chapter 17.20a (formerly 17.14).
    “the principal objective and purpose to be served by this classification and its application are to create a living environment of the highest standards for single-family detached dwellings”
  • Zoning districtsPublished (with conditions)

    Zoning districts inside Hawthorne city limits (Title 17 residential, commercial, industrial, open space zones).

    • Title 17 index lists residential zone chapters R-1 through R-4, commercial C-2, C-3, C-M and C-R, industrial M-1 and M-2, open space and horticultural zones. Zoning map not opened.
    “chapter 17.20a r-1 zone (§ 17.20a.010 – § 17.20a.030) chapter 17.20b r-2 zone (§ 17.20b.010 – § 17.20b.030)”
  • Minimum lot sizeSpecified

    Single-family detached dwellings in the R-1 Low-Density Residential zone inside Hawthorne city limits (main single-family district; no agricultural or rural-residential district was found in Title 17 index).

    • Table note 1: lot size is in square feet.
    • Lot width 50 ft and lot depth 100 ft minimums also apply.
    • Chapter renumbered from 17.14 to 17.20a by Ord. 2263 (6/23/2026).

    minimum lot size: >= 5000 sq ft · minimum lot width: >= 50 ft · minimum lot depth: >= 100 ft

    “single-family detached dwelling 5,000 50 100 15 5/5 4 5 50% 22 — accessory dwelling unit (adu) see california government code §§ 66310 through 66342.”
  • SetbacksSpecified

    Single-family detached dwellings in the R-1 Low-Density Residential zone inside Hawthorne city limits.

    • Table note 2: for garage facing street, minimum setback of 18 feet required.
    • Table note 3: side setback is 10% of lot width up to 5 feet, but not less than 3.5 feet.
    • Table note 4: an additional setback of 5 feet shall apply to the second story adjacent to a street-side yard.
    • Table note 5: on through lots the rear setback shall be the same as required for front setback.

    minimum front setback: 15 ft (18 ft for garage facing street) · minimum side setback (interior/street): 5 ft (10% of lot width up to 5 ft, not less than 3.5 ft) · minimum rear setback: 5 ft (through lots: same as front setback)

    “2 for garage facing street, minimum setback of 18 feet required. 3 side setback is 10% of lot width up to 5 feet, but not less than 3.5 feet.”
  • Lot coverageSpecified

    Single-family detached dwellings in the R-1 Low-Density Residential zone inside Hawthorne city limits.

    • Maximum lot coverage for R-1 single-family detached dwelling per table; PUD two-unit development is 75% under its own row.

    maximum lot coverage: <= 50 % (planned unit development, 2 units only: 75%)

    “single-family detached dwelling 5,000 50 100 15 5/5 4 5 50% 22 — accessory dwelling unit (adu) see california government code §§ 66310 through 66342.”
  • Building heightSpecified

    Single-family detached dwellings in the R-1 Low-Density Residential zone inside Hawthorne city limits.

    • Table note 6: 12 feet maximum on lots less than 40 feet average width and less than 5,000 square feet.

    maximum building height: <= 22 ft (12 ft on lots less than 40 ft average width and less than 5,000 sq ft)

    “6 12 feet maximum on lots less than 40 feet average width and less than 5,000 square feet.”
  • Manufactured homesAllowed (with conditions)

    Mobile homes in the R-1 zone inside Hawthorne city limits.

    • Listed as a permitted use subject to the R-1 table standards: 5,000 sq ft minimum lot, 12 ft maximum height.
    • Mobile home row carries a 12 ft maximum height rather than the 22 ft single-family limit.

    maximum building height: <= 12 ft

    “mobile home 5,000 50 100 15 5/10 5 50% 12 — assembly use (cup)”
  • Mandatory utility hookupSewer (with conditions)

    New buildings and structures inside Hawthorne city limits that connect to the city sewer.

    • Connection to the public sewer requires a city engineer sewer connection permit and payment of fees (§ 13.56.010).
    • Erecting or altering a building requires compliance with the sewer article first (§ 13.56.020).
    • Connection fees are in Chapter 13.60; the mandatory-connection distance rule was not located in the pages opened.
    “it is unlawful for any person to make or cause to be made, a connection to a public sewer without first obtaining a sewer connection permit from the city engineer and paying the established fees as prescribed in this article for such connection.”
  • Subdividing landRegulated (with conditions)

    Land divisions inside Hawthorne city limits.

    • Title 16 (Subdivisions, §§ 16.04.010 to 16.64.030) governs subdivisions; its text was not opened.
    • Urban lot splits and two-unit developments are in Chapter 17.24f (§§ 17.24f.010 to 17.24f.050).
    “title 16 subdivisions (§ 16.04.010 &ndash; § 16.64.030)”
  • Short-term rentalsLimited

    Short-term rentals inside Hawthorne city limits.

    • Requires a city short-term rental permit, business license and TOT registration; permit expires each Dec 31.
    • Eligible only in single-family residences, duplexes, triplexes, PUDs and multifamily dwellings of up to four units; not in Section 8 housing or accessory dwelling units (§ 17.24e.030).
    • Vacation rentals (non-primary residence) limited to 90 days per calendar year and not allowed in industrial or commercial zones (§ 17.24e.050).
    • Primary residence must be occupied at least nine months per year; secondary residence permits limited to 10 per year (§ 17.24e.010).
    • Host or owner must be reachable 24 hours; guest log and parking of one space for host and one for guest required (§ 17.24e.060).
    “an owner shall obtain a short-term rental permit from the city before renting a dwelling unit as a short-term rental or advertising the availability of a short-term rental.”
  • Permit processPartial

    Building permit applications inside Hawthorne city limits.

    • Applications are deemed abandoned 180 days after filing unless pursued in good faith or a permit is issued; the building official may grant extensions of up to 90 days each, to no more than two years from submittal (§ 15.04.050).
    • Application fees and the full submittal checklist were not located.

    application abandonment period: 180 days (extensions of up to 90 days each)

    “an application for a permit for any proposed work shall be deemed to have been abandoned 180 days after the date of filing unless such application has been pursued in good faith or a permit has been issued.”

Still unanswered

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

  • Owner-builder exemption — Owner-builder permit exemption inside Hawthorne city limits.
  • Minimum dwelling size — Minimum dwelling floor area inside Hawthorne city limits.
  • Living in an RV — Long-term RV occupancy on private land inside Hawthorne city limits.
  • Camping on your land — Temporary camping on private land inside Hawthorne city limits.
  • Tiny homes — Tiny homes inside Hawthorne city limits.
9 more unanswered
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • 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 Hawthorne 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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