ADU Builder in Huntington Park, CA: Local Rules, Fees and Permits

How big can an ADU be on a Huntington Park lot?

The 2023 Housing Element says the city is replacing its second dwelling unit rules. Huntington Park's zoning code defines a second dwelling unit as a unit on the same lot as the primary single-family home, attached or detached, with a full bath, a kitchen and no more than one bedroom. The element says the city allows second units in the R-L zone district, and that the current ordinance still calls for a conditional use permit and two covered parking spaces, a lot of at least 6,500 square feet, parcel width of 50 feet and depth of 80 feet, an attached unit capped at 30 percent of the main dwelling's existing living area, and a detached unit of 750 square feet. The element calls those provisions inconsistent with state ADU law and says the city processes ADU applications under state requirements until it revises the ordinance. State law sets the floor a city must allow. A detached ADU may reach 1,200 square feet, an attached ADU may reach 50 percent of the existing primary dwelling, local size caps may not fall below 850 square feet, or 1,000 square feet for a unit with more than one bedroom, and a city must permit at least 800 square feet with four-foot side and rear setbacks. Detached height starts at 16 feet and rises to 18 feet within a half mile of a major transit stop, and an attached ADU may reach 25 feet.

How long does an ADU permit take in Huntington Park?

State law sets the backstop for the city's review. Government Code Section 66317 requires the city to give written notice of whether an application is complete within 15 business days, to approve or deny a complete application within 60 days, to treat a completed application it has not acted on in that window as approved, and to toll the 60 days if the applicant asks for a delay. The city's own process pages show how a file moves. A Minor Development Permit from the Planning Division comes first, with two sets of plans 24 inch by 36 inch, a required fee of $412.00, and re-submittals that include the earlier plans with the corrections marked. Building plan check then takes three sets of plans for a new single-family residence, an addition, or alterations to a single-family residence, with partially completed plans not accepted, and structural calculations in two sets wet stamped by a California Registered Architect or Civil Engineer or Structural Engineer. Plans can be uploaded through the Building and Safety plan check portal at any hour, though a submittal outside business hours is processed the next business day, and Building and Safety forwards plans to Planning for zoning clearance. Review does not begin until the plan review fees are paid. The city publishes no review-day count for ADU files, so the 60-day state deadline is the number to plan around.

What does the City of Huntington Park charge for an ADU permit?

Two city fee documents decide what a permit costs. The Minor Development Permit application for an ADU carries a required fee of $412.00, and re-submittals must include the previously submitted plans with the corrections made by the Planning Division. The Master Fee Schedule, effective January 1, 2026, applies a Permit Issuance Fee of $100.00 to every permit issued, whatever the permit type, and it sets plan check fees after the second submittal at $646.00 per hour, with all initial plan check fees covering the first plan check and one recheck only. The schedule also states that plan check, permit and inspection fees not specifically listed in it are the County of Los Angeles fees in effect at the time of permit issuance, so ask the counter for the County figures as well. State law limits one line item. Government Code Section 66311.5 says no impact fee may be charged on an ADU with 750 square feet of interior livable space or less, or on a junior ADU of 500 square feet or less, and that impact fees above 750 square feet must be charged in proportion to the square footage of the primary dwelling.

How much does an ADU cost in Huntington Park?

L Square publishes six configured prefab prices on its Orange County cost page. Model 600 at $180,000 for 600 square feet with 2 bedrooms and 1 bath, Model 800A and Model 800B at $240,000 each for 800 square feet with 2 bedrooms and 2 baths, Model 1000A and Model 1000B at $295,000 each for 1,000 square feet with 3 bedrooms and 2 baths, and Model 1200 at $354,000 for 1,200 square feet with 3 bedrooms and 2 baths. Treat those as typical unit price ranges for the factory-built shell and interior rather than a lot price. Site work, utility routing, foundation design, permits and finish selections are quoted per property, and the city's own fees listed above sit on top of that.

What should I check before building an ADU in Huntington Park?

Four things decide whether a project moves. Zoning and the current ordinance come first. Huntington Park's adopted Housing Element says the local second dwelling unit rules still require a conditional use permit and two covered parking spaces, a 6,500 square foot lot and an attached unit capped at 30 percent of the main dwelling's living area, and that the city will process ADU applications under state requirements while it revises them, so confirm the current status with the Planning Division before you design. Parking follows state rules. Parking for an ADU cannot exceed one space per unit or per bedroom, whichever is less, and no replacement parking is required when a garage or carport is converted. Utilities and fees come next. A new utility connection can carry a connection fee or capacity charge. Then check the market and the paperwork. The city's Housing Element records ADU building permits issued of 6 in 2018, 10 in 2019, 24 in 2020 and 16 in 2021, with the table showing an average of 14 across three years and a projection of roughly 112 ADUs during the 2021-2029 planning period, so a busy review calendar is realistic. HCD's review of the city's draft element also required the city to commit to monitoring ADUs by income category.

Official Huntington Park ADU sources

• The city's Minor Development Permit application guidelines list an accessory dwelling unit among the projects that need a permit, ask for two sets of plans 24 inch by 36 inch with the application, set a required fee of $412.00, and require re-submittals to include the previously submitted plans with the corrections made by the Planning Division. Official source
• The city's Plan Check and Permit Process page says building plan check requires three sets of plans for new single-family residence, addition, and alterations to the single-family residence, that partially completed plans will not be accepted, that structural calculations come as two sets wet stamped and signed by a California Registered Architect or Civil Engineer, or Structural Engineer for a two story new single-family residence and room additions, and that plans are submitted at the Planning and Zoning counter at City Hall, 6550 Miles Avenue. Official source
• The city's Building and Safety Division states that any project submitted on or after January 1st, 2026 must comply with the new 2025 California Building Standards Code, and lists the 2025 California Building Code, 2025 California Residential Code, 2025 California Electrical Code, 2025 California Mechanical Code and 2025 California Plumbing Code, with division hours Monday through Thursday from 7:00 a.m. to 5:00 p.m. at 6550 Miles Avenue. Official source
• The city's Electronic Plan Check Submittal page says projects can be submitted 24/7, that a submittal made outside business hours is processed the following business day, that Building and Safety forwards the plans to the Planning Division for zoning clearance where applicable, and that the plan check review cannot begin until the plan review fees have been paid and the payment receipt has been provided to the Building Permit Counter. Official source
• The city's Master Fee Schedule for fiscal year 2025/2026, effective January 1, 2026, applies a Permit Issuance Fee of $100.00 to every permit issued regardless of permit type, sets plan check fees after the second submittal at $646.00 per hour with all initial plan check fees covering the first plan check and one recheck only, and states that plan check, permit and inspection fees not specifically delineated in the schedule are the County of Los Angeles fees in effect at the time of permit issuance. Official source
• The city's adopted 2021-2029 Housing Element, adopted October 17, 2023, defines a second dwelling unit in Zoning Code Section 9-1.203 as a dwelling unit on the same lot as the primary single-family dwelling, attached or detached, with independent living facilities for no more than two persons, a full bath, a kitchen and no more than one bedroom, and says the city provides for second units in the R-L zone district while the ordinance requires a conditional use permit and two covered parking spaces and a minimum 6,500 square foot lot size, which it calls inconsistent with state ADU law. Official source
• The Housing Element's zoning constraints section states the size of an additional second unit shall not exceed 30 percent of the existing living area of the main dwelling for an attached second unit, or 750 square feet for a detached unit, and requires a minimum parcel width of 50 feet and depth of 80 feet. Its accessory dwelling unit production table records ADU building permits issued of 6 in 2018, 10 in 2019, 24 in 2020 and 16 in 2021, an average of 14 across three years, and a projection of approximately 112 ADUs during the 2021-2029 planning period. Official source
• In its review of the city's draft housing element, the California Department of Housing and Community Development wrote that the element did not address its finding on accessory dwelling unit monitoring, and that Action 2-9, which covers accessory dwelling units, was revised to commit the city to monitor ADUs by income category with a stated timeline for that monitoring and for any further action if the city misses the target numbers. Official source
• California Government Code Section 66317 requires a permitting agency to give written notice of whether an accessory dwelling unit application is complete no later than 15 business days after receiving it, to approve or deny a completed application within 60 days, to treat a completed application it has not acted on in that time as approved, and to toll the 60 days while the applicant requests a delay. Official source
• California Government Code Section 66314 provides that the total floor area for a detached accessory dwelling unit shall not exceed 1,200 square feet, that an attached accessory dwelling unit shall not exceed 50 percent of the existing primary dwelling, that parking for an accessory dwelling unit shall not exceed one parking space per unit or per bedroom whichever is less, and that a local agency shall not require off-street parking spaces to be replaced when a garage or carport is converted to an accessory dwelling unit. Official source
• California Government Code Section 66321 provides that a local agency shall not set a maximum accessory dwelling unit size below 850 square feet of interior livable space, or 1,000 square feet for a unit with more than one bedroom, must permit an accessory dwelling unit of at least 800 square feet with four-foot side and rear yard setbacks, and must allow a height of 16 feet for a detached unit and 18 feet within one-half of one mile walking distance of a major transit stop. Official source
• California Government Code Section 66311.5 provides that a local agency shall not impose any impact fee upon the development of an accessory dwelling unit that has 750 square feet of interior livable space or less or a junior accessory dwelling unit that has 500 square feet or less, and that impact fees charged for a larger accessory dwelling unit must be charged proportionately in relation to the square footage of the primary dwelling unit. Official source
• The California Department of Housing and Community Development's ADU Handbook states that state law mandates no owner-occupancy requirement for an accessory dwelling unit under Government Code section 66315, that rentals of an accessory dwelling unit or a junior accessory dwelling unit must be for terms longer than 30 days under sections 66323 and 66333, and that fire sprinklers are not required for an accessory dwelling unit if they are not required for the primary residence. Official source