Agoura Hills Zoning and ADU Guide for Homeowners

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team.

Agoura Hills offers a Pre-Approved Standard ADU Plan Program through its Building and Safety Division, with three free pre-reviewed plans, and regulates ADUs in Zoning Code sections 9283 through 9283.5. This guide explains the city’s pre-approved plan program, which lots can have an ADU or junior ADU, the size and parking rules the city adopted in 2021, and why the state housing department’s 2023 review means you should confirm current standards with Planning before you design or buy.

Agoura Hills ADUs at a glance

Program	Pre-Approved Standard ADU Plan Program, Building and Safety Division
Plans offered	Three pre-reviewed plans: a studio, a one-bedroom and a two-bedroom, prepared by RRM Design Group
Styles	Cottage, Ranch and Spanish, with porch variations
Eligible lots	ADU and JADU on lots with an existing or proposed single-family home; ADU also on lots with an existing duplex or multifamily units; JADU only on single-family lots
Size (2021 ordinance 21-456)	Up to 850 sq ft for a studio or one-bedroom ADU and up to 1,000 sq ft with more than one bedroom; attached ADU not over 50% of the primary home but never limited below 800 sq ft
Review time (2021 ordinance)	60 days, down from 120
Parking (2021 ordinance)	One space per ADU unless an exemption applies, such as within one-half mile walking distance of public transit or inside existing space
Planning contact	Planning and Zoning (818) 597-7328

The pre-approved ADU plan program

The city’s program is run by the Building and Safety Division and is meant to simplify permitting for ADUs built to a repeatable design.

It offers three pre-reviewed, code-compliant plans, a studio, a one-bedroom and a two-bedroom, each available in Cottage, Ranch and Spanish styles with porch variations, so homeowners can choose exterior materials, doors and windows.

The plans were prepared by RRM Design Group and are available for free online or at City Hall. The permit guide includes a checklist, plan options, a sample site plan, a hold harmless and indemnification form and FAQs.

According to the city, using a pre-approved plan generally eliminates the need for plan check and its fees and reduces review time. Residents still need a prepared site plan, the selected plan set and a completed building permit application. The program does not remove the need for the permit itself or for other required reviews, such as grading and drainage, septic systems and utilities, or fire sprinklers where applicable.

Which lots and unit types the city allows

The city says ADUs and junior ADUs are allowed on properties with an existing or proposed single-family dwelling, and ADUs are also permitted on lots with an existing duplex or multifamily units, while junior ADUs are limited to single-family properties.

The city lists several ways to create a unit: converting an existing legal accessory structure, building an attached addition to a single-family home, building a detached unit, converting non-habitable portions of a multifamily building, and adding to an existing legal accessory structure.

What the 2021 ordinance set

The city’s Housing Element describes Ordinance 21-456, adopted in August 2021 to update the zoning code’s ADU rules.

It allows ADUs and junior ADUs in all residential zones and in the commercial mixed use and open space restricted zones, cut processing time from 120 to 60 days, set maximum sizes of 850 square feet for a studio or one-bedroom and 1,000 square feet for units with more than one bedroom, and capped an attached ADU at 50 percent of the primary home’s floor area without reducing the allowed size below 800 square feet.

It requires one parking space per ADU unless an exemption applies, for example the unit is within one-half mile walking distance of public transit, is inside the primary dwelling or another existing structure, or is in a historic district.

The state’s 2023 review and fire zones

The California Department of Housing and Community Development reviewed the city’s ordinance in a letter dated February 3, 2023, and listed provisions that it said do not comply with state ADU law.

The letter lists junior ADU definition, the Very High Fire Hazard Severity Zone sections (9283 and 9283.2), height, building separation, detached ADU setbacks, conversion of an existing parking structure, setbacks, sale of an ADU separate from the primary dwelling, ADU size and the Old Agoura Design Overlay.

The city’s Housing Element also says the city committed to update its ordinance to comply. Because the details may have changed since, ask Planning for the standards in effect when you apply, especially if your lot is in a fire zone or the Old Agoura overlay.

Garage conversions and unpermitted units

Older Agoura Hills homes may have a converted garage or a backyard unit built without permits.

The city’s building rules treat work started without a permit as subject to a special investigation and an investigation fee equal to the permit fee, and the Code Enforcement Division lists unpermitted construction among its priorities.

The ADU path is a way to legalize some units, but it involves plans, fees and inspections. Our permits guide and code enforcement guide explain those two sides.

State ADU law and Agoura Hills

California’s ADU statute, Government Code section 66314 and following, sets a floor that every city must follow, and local ordinances fill in the details.

The state requires ministerial review within 60 days of a complete application, bars a city from requiring more than a limited set of standards, and generally allows an ADU or conversion inside existing space without added setbacks.

The California Department of Housing and Community Development (HCD) publishes a handbook and keeps a list of the state requirements. Because state law changes often, treat the city’s current ordinance and handout as the final word on size, height, parking and fees for your lot.

ADUs, garage conversions and selling an Agoura Hills house

Many older homes have a converted garage or a backyard unit built without permits. Buyers and lenders ask about them, and California sellers generally disclose known unpermitted work. Our guide to selling as-is with unpermitted work explains the rules, and our Prop 13 guide explains how new construction can affect property tax. Before you list:

• Check city records for permits on any ADU, conversion or addition.
• Ask Planning whether the structure could qualify under current rules.
• Estimate plans, fees and corrections needed to legalize it.
• Compare that with selling as-is and letting a cash buyer take on the legalization.

Questions to ask Planning before you design

• Does my lot and zone allow an ADU, a junior ADU, or both?
• Is a pre-approved or pre-reviewed ADU plan available?
• What are the current impact, utility and school fees for the size I am considering?
• Can my existing garage or accessory structure be converted without changing its footprint?
• Are there fire, slope, easement or utility constraints on my lot?

Junior ADUs and garage conversions in more detail

State law treats a junior ADU as a unit of up to 500 square feet created inside the walls of an existing or proposed single-family home, with an efficiency kitchen and a recorded restriction that keeps it from being sold apart from the house.

A garage conversion is a different path: the unit replaces the garage, and state law generally does not require the city to demand replacement parking. Both are common sources of unpermitted space in older Agoura Hills neighborhoods, which is why buyers’ agents and appraisers ask for the permit record.

If a conversion was done without a permit, the usual fix is to submit as-built drawings, pay the fees and pass inspection, which can take months and cost real money.

Fees, utilities and property tax

State law limits the impact fees a city can charge on smaller ADUs and on conversions of existing space, and it limits when a separate utility connection can be required.

Larger new units can still carry impact fees, school fees and water or sewer connection charges, so ask for an itemized estimate before you commit to plans. New construction is generally reassessed for property tax under Prop 13, which means an ADU can raise the bill for the whole property. Our Prop 13 guide explains how reassessment works.

Why ADUs matter for resale

A permitted ADU can add rental income and appeal for some buyers, but an unpermitted one can complicate financing and appraisal. Lenders typically want permitted living area, and an appraiser may not count unpermitted space.

Because an ADU generally cannot be sold separately from the main home, its value comes through the sale of the whole property.

If you inherited a house with an old backyard unit, or bought one with a converted garage, check what the city has on file before you decide how to sell. Our probate home sale guide covers inherited property.

How to sell a house in Agoura Hills

1. Ask the city for the permit record on any ADU or conversion.
2. Collect plans, inspection records and any city notices.
3. Request a no-obligation cash offer for the house as it stands.
4. Choose your closing date.
5. Close with no repairs, legalization or showings required.

See also our Agoura Hills page, selling as-is in Agoura Hills, the Agoura Hills cash offer process and the Los Angeles County hub.

Frequently asked questions

Does Agoura Hills have pre-approved ADU plans?

Yes. The Building and Safety Division offers three free pre-reviewed plans, a studio, a one-bedroom and a two-bedroom, each in Cottage, Ranch and Spanish styles.

Does a pre-approved plan skip all city review?

No. The city says it generally eliminates plan check and associated fees, but you still need a permit and other reviews such as grading and drainage, septic and utilities, or fire sprinklers where applicable.

Can I build a junior ADU on any lot?

The city says junior ADUs are limited to properties with an existing or proposed single-family dwelling, while ADUs are also allowed on lots with an existing duplex or multifamily units.

How large can an Agoura Hills ADU be?

The city’s 2021 ordinance, as described in its Housing Element, allowed up to 850 sq ft for a studio or one-bedroom and up to 1,000 sq ft for more than one bedroom. HCD’s 2023 letter flagged the size provision, so confirm with Planning.

Is parking required for an ADU?

The 2021 ordinance requires one space per ADU unless an exemption applies, such as being within one-half mile walking distance of public transit or inside existing space. Confirm current rules with Planning.

Can I sell my Agoura Hills house with an unpermitted ADU or garage conversion?

Yes. You can disclose it and sell as-is, including to a cash buyer. Our statewide guide explains the disclosure rules.

More guides

• We Buy Houses in Agoura Hills
• We Buy Houses in Los Angeles County
• Los Angeles County Property Tax Guide
• Agoura Hills Building Permits Guide
• Agoura Hills Code Enforcement Guide
• Calabasas Building Permits Guide
• Hidden Hills Building Permits Guide
• All California Guides

Sources

• City of Agoura Hills: Pre-Approved Standard ADU Plan Program
• HCD: Review of Agoura Hills’ ADU Ordinance (February 3, 2023)
• Agoura Hills Housing Element, 6th cycle draft
• City of Agoura Hills: Community Development

This guide is general information from public sources, not legal advice. Confirm current rules, fees and hours with the city.