ADU Builder in Agoura Hills, CA: City Rules, Fees and Permits

What are the ADU rules in Agoura Hills?

State law sets the floor and the city sets the rest, and in Agoura Hills that part is being rewritten. Government Code Section 66321 stops the city from setting an accessory dwelling unit maximum below 850 square feet of interior livable space, or 1,000 square feet for a unit with more than one bedroom, and requires the city to allow at least 800 square feet of interior livable space with four-foot side and rear yard setbacks. The same section requires the city to allow a 16-foot height for a detached unit and 18 feet within one-half of one mile of a major transit stop. On the city's own ordinance, the Department of Housing and Community Development wrote on May 7, 2025 that Agoura Hills ADU Ordinance No. 21-456 did not match state law in several areas, including a 10-foot separation rule in the Very High Fire Hazard Severity Zone and a covenant requirement, and on October 6, 2025 asked the city to repeal the outdated ordinance after the city said a replacement would be adopted in December 2025.

How long does an ADU permit take in Agoura Hills?

State law sets the clock and the city adds steps on top of it. Government Code Section 66317 requires the city to tell you in writing within 15 business days whether your application is complete and to approve or deny a complete application within 60 days, and a complete application the city does not act on inside that window counts as approved. Agoura Hills reviews an application for completeness first, and the city's planning checklist says that review can take up to 30 days depending on department workload. The pre-approved plan route is faster: the city's own FAQ says review runs about five business days for a first review and five business days for a second review. Using a pre-approved plan set removes the building plan review fee but not the permit itself and not the reviews for grading and drainage, septic systems and utilities, or fire sprinklers where they apply. Los Angeles County Fire Department approval and the school district impact fee receipt come before the city issues the permit.

How much does an ADU permit cost in Agoura Hills?

The city's Planning Division fee schedule, revised July 1, 2025, lists a restrictive covenant fee of $866.00 each for an ADU, a zoning clearance plan check of $325.00 each, a charge of $1,162.00 each for plan checks after a third review, and a pre-application review planning fee of $4,804.00 each. Some fees drop out by size. Government Code Section 66311.5 bars any impact fee on an accessory dwelling unit of 750 square feet of interior livable space or less and on a junior accessory dwelling unit of 500 square feet or less, and requires impact fees on a larger unit to be charged in proportion to the square footage of the primary dwelling. School districts may charge an impact fee on an ADU larger than 500 square feet under Section 17620 of the Education Code. Utility connection and capacity charges are a separate line, because the state treats an ADU as part of the lot for that purpose unless it was built at the same time as a new single-family dwelling.

How much does an ADU cost in Agoura Hills?

Start with L Square's published prefab prices, then add the site work. The configured models are Model 600 at $180,000 for 600 square feet with 2 bed and 1 bath, Model 800A and Model 800B at $240,000 each for 800 square feet with 2 bed and 2 bath, Model 1000A and Model 1000B at $295,000 each for 1,000 square feet with 3 bed and 2 bath, and Model 1200 at $354,000 for 1,200 square feet with 3 bed and 2 bath. Those are configured model prices from the lscontractor.com cost guide, not a quote for your lot, and they do not cover sewer and water connections, electrical panel work, foundations on sloped ground, permit fees, or finish upgrades. L Square is a licensed California contractor, CSLB #1095476, and prices an actual project after a site visit. Call (949) 374-7980 to set one up.

What should I check before you build an ADU in Agoura Hills?

Five checks decide whether your lot can carry a unit. Fire: most properties in Agoura Hills sit in a High or Very High Fire Hazard Severity Zone, so fuel modification may be required, and the Los Angeles County Fire Department wants an apparatus access road or driveway where any part of the proposed structure is more than 150 feet from the street property line. Grading: a grading plan signed by a licensed engineer and a grading permit are required when grading goes over 50 cubic yards. Trees: an oak tree permit applies when work enters the root or canopy protection zone of an oak. Utilities: an ADU on a septic system needs Public Health approval and a detached ADU needs SCE approval. Also expect a separate address for the unit, no gas line, a PV solar system under the 2022 California Energy Code for a newly constructed detached unit, and all applications filed through the MyGovernmentOnline system with 24 by 36 inch plan sheets.

Does Agoura Hills have free pre-approved ADU plans?

Yes, and they are the fastest route through the city. The Building and Safety Division offers a Standard Plan Program with three pre-reviewed, code-compliant ADU construction plans, a studio, a one-bedroom and a two-bedroom option, each in three architectural styles with porch variations, prepared by the RRM Design Group and available free online or at City Hall. The plan sizes are 550 square feet for the studio, 750 square feet for the one-bedroom and 1,000 square feet for the two-bedroom, each with a slab on grade or raised foundation option. The city's FAQ says the pre-approved drawings still need a site plan and property-specific documents, and any structural change or added floor area pushes the application out of the program and back into standard review.

Official Agoura Hills ADU sources

• The city's Building and Safety Division offers a Standard Plan Program with three pre-reviewed, code-compliant ADU construction plans, a studio, a one-bedroom and a two-bedroom option, each available in three architectural styles with porch variations, and says the plans were prepared by the RRM Design Group, are available for free online or at City Hall, reduce plan check time, and still require a Pre-Approved ADU permit and other reviews such as grading and drainage, septic systems and utilities, or fire sprinklers where applicable. Official source
• The city's pre-approved ADU FAQ lists three plan types, a 550 sf studio, a 750 sf one-bedroom and a 1,000 sf two-bedroom in Cottage, Ranch and Spanish styles, and says review takes about five business days for a first review and five business days for a second. It also says the plans are All-Electric with no gas allowed, a PV solar system is required under the 2022 California Energy Code section 150.1(c) for newly constructed detached ADUs, and school districts may levy impact fees for ADUs greater than 500 square feet under Section 17620 of the Education Code. Official source
• The city's pre-approved ADU permit guide says valuation for the permit is the contractor's bid for the fair-market cost of labor and materials, that an address suffix A is assigned to the ADU, that Los Angeles County Fire Department approval is required at submittal with final sign off before the city's final inspection, that a School District impact fee receipt is required prior to permit issuance, that County Environmental Health approval is required at submittal for properties on septic systems, and that gas infrastructure is not allowed with the Pre-Approved ADU plans. Official source
• The city's Accessory Dwelling Units planning application checklist says all applications must be submitted electronically through the MyGovernmentOnline system, that the planning review for completeness may take up to 30 days depending on the current workload of the department, that a restrictive covenant fee must be paid before approval of a final building permit, that a title report no older than 30 days is required, that detached ADUs need SCE approval and ADUs on septic need Public Health approval, and that an oak tree permit is required for work in the tree protection zone of an oak tree. Official source
• The city's pre-approved ADU permit checklist says lot coverage information is needed if the ADU is over 800 SF, that equestrian facilities must be shown if the ADU is over 800 SF and the property is in Old Agoura, and that a covenant is required if the ADU is under 800 SF. Official source
• The Planning Division fee schedule revised July 1, 2025 lists a Restrictive Covenant fee for an ADU of $866.00 each, a Plan Check Zoning Clearance fee of $325.00 each, Plan Checks After 3rd Review of $1,162.00 each, and a Pre-Application Review Planning Fee of $4,804.00 each. Official source
• The Department of Housing and Community Development wrote on May 7, 2025 that the city's ADU Ordinance No. 21-456 was inconsistent with state ADU law, including a requirement to maintain a 10-foot separation between the accessory dwelling unit and any other structure in the Very High Fire Hazard Severity Zone, a requirement to replace parking spaces when a garage is converted, a covenant requirement, and a discretionary Fire Safety Review, and asked the city to respond with a plan of action by June 7, 2025. Official source
• The Department of Housing and Community Development wrote on October 6, 2025 that the city had told it a new ADU ordinance would be adopted in December 2025 without saying how the city would process applications in the meantime, asked the city to repeal the outdated, noncompliant ordinance so applicants do not rely on an ordinance still in the code of ordinances that does not meet state ADU law, and requested a response by November 5, 2025. Official source
• In its February 3, 2023 findings letter on the city's ADU ordinance, the Department of Housing and Community Development wrote that the ordinance states in several places that the height limitation for ADUs is 16 feet, that detached ADUs in the Very High Fire Hazard Severity Zone must provide a minimum setback of five feet from the side and rear lot lines, and that the maximum gross area of a new detached ADU in an existing legally established accessory structure may not exceed 850 square feet for a one bedroom and 1,000 square feet for an ADU with more than one bedroom. Official source
• California Government Code Section 66317 requires a permitting agency to give written notice of whether an accessory dwelling unit application is complete not 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 66321 provides that a local agency shall not set a maximum accessory dwelling unit size below eight hundred fifty square feet of interior livable space, or one thousand square feet for an accessory dwelling unit that provides more than one bedroom, must permit an accessory dwelling unit with at least 800 square feet of interior livable space and four-foot side and rear yard setbacks, and must allow a height of 16 feet for a detached accessory dwelling unit and 18 feet within one-half of one mile walking distance of a major transit stop. 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 requirements shall not exceed one parking space per accessory dwelling unit or per bedroom, whichever is less, and that the local agency shall not require that those off-street parking spaces be replaced when a garage, carport or covered parking structure is demolished or converted for an accessory dwelling unit. Official source
• California Government Code Section 66311.5 provides that a local agency, special district or water corporation shall not impose any impact fee on an accessory dwelling unit of 750 square feet of interior livable space or less or on a junior accessory dwelling unit of 500 square feet or less, that impact fees on a larger accessory dwelling unit shall be charged proportionately to the square footage of the primary dwelling unit, and that an accessory dwelling unit shall not be treated as a new residential use for utility connection fees unless built with a new single-family dwelling. Official source
• California Government Code Section 66315 provides that no additional standards, other than those provided in Section 66314, shall be used or imposed, including an owner-occupant requirement, except that a local agency may require that the property may be used for rentals of terms 30 days or longer. Official source