ADU Construction Calabasas

We design and build ADU's in Calabasas California

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Build a Legal, Beautiful, and Functional Accessory Dwelling Unit in Calabasas, CA

If you’re a Calabasas homeowner looking to add more space or generate rental income, building an Accessory Dwelling Unit (ADU) is a smart investment. At All Exclusive Construction, we specialize in designing and building ADUs that comply with local zoning laws and enhance both the functionality and value of your property.

Calabasas, like many cities in California, has adopted state legislation that makes it easier for homeowners to build ADUs on residential properties. However, local zoning rules, lot coverage limits, height restrictions, and design guidelines still apply—especially in neighborhoods with HOAs or hillside grading issues. Whether you're in The Oaks, Mountain Park Estates, or Calabasas Highlands, our team understands the city’s permitting process, building code requirements, and neighborhood-specific constraints.

We’ll guide you through every step, from site evaluation and design to permit approval and final construction. Whether you want to build a detached ADU for rental income, a garage conversion, or an attached in-law suite for multigenerational living, we create solutions that blend seamlessly with your home and meet all City of Calabasas development standards.

What Are The Requirements To Build An ADU In Calabasas?

Building an Accessory Dwelling Unit (ADU) in Calabasas requires compliance with both California state laws and specific local ordinances enforced by the City of Calabasas. While state regulations have made it easier to build ADUs, Calabasas maintains additional guidelines that homeowners must follow. Here are some of the key requirements:

    • Zoning and Lot Eligibility: ADUs are allowed on most single-family and multifamily residential lots in Calabasas. However, your property must meet minimum lot size and setback requirements, and hillside or environmentally sensitive areas may have additional restrictions.
    • Size Limits: Detached ADUs in Calabasas are generally limited to 1,200 square feet, while attached ADUs cannot exceed 50% of the existing home’s floor area. Junior ADUs (JADUs) are limited to 500 square feet and must be located within the existing footprint of the home.
    • Setbacks: A minimum of 4 feet from side and rear property lines is typically required for detached ADUs. Front yard setbacks and height limits may vary based on your zoning district.
    • Parking: In many cases, additional parking is not required, especially if the ADU is located within half a mile of public transit or if you’re converting an existing garage.
    • Design Standards: The ADU must match the architectural character of your primary home, including roof style, materials, colors, and finishes—especially in design-controlled neighborhoods like The Oaks or Westridge.
    • Permit Approval: You must obtain a building permit and submit plans to the City of Calabasas Building & Safety Division. Our team handles the full permitting process on your behalf to ensure compliance and avoid delays.

Navigating ADU regulations in Calabasas can be complex, but with All Exclusive Construction, you’ll have a team that knows the local process inside and out. We make it easy to build a legal, high-quality ADU that adds long-term value to your home.

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How Much Does An ADU Cost?

The cost for accessory dwelling units can vary depending on many different factors

Attic ADU

This would be for the complete conversion of your unused attic space into a fully functional and rentable ADU.

Cost $45k-$75k+
Depending On Size and Scope.

Above Garage ADU

This would be for converting that unused space above your garage into a functional ADU.

Cost $75k-$150k+
Depending On Size and Scope.

Detached ADU

This would be for a completely detached, stand-alone, ADU on your property.  This is entirely new construction.

Cost $75k-$250k+
Depending On Size and Scope.

Frequently Asked Questions About Accessory Dwelling Units

An ADU is an attached or detached residential dwelling unit located on the same property as a primary residence. It provides complete independent living facilities, including living, sleeping, eating, cooking, and sanitation.

A JADU is a smaller unit, no more than 500 square feet, contained entirely within the walls of an existing or proposed primary residence. It may have a kitchenette and separate sanitation facilities or may share sanitation facilities with the primary structure.

In most cases, yes—you can build an ADU on your property in Calabasas, provided your lot is zoned for residential use and meets certain local requirements. The City of Calabasas allows both detached and attached ADUs on single-family and multi-family residential properties, in compliance with California state law. However, additional considerations—such as lot size, setback distances, slope restrictions, and HOA rules—may affect what type of ADU you can build and where it can be placed.

If your property is located in a hillside area, designated open space zone, or within a neighborhood with strict design guidelines (such as The Oaks, Calabasas Highlands, or Mountain Park Estates), your project may require additional review or modifications. Our team at All Exclusive Construction will evaluate your lot, confirm eligibility, and guide you through every step of the process to make sure your ADU is built legally and efficiently.

In Calabasas, ADU size limits depend on the type of ADU you’re building and the configuration of your property. Here’s a general breakdown based on current city and state guidelines:

    • Detached ADUs can be up to 1,200 square feet, regardless of the size of the primary residence.
    • Attached ADUs are limited to 50% of the floor area of the existing home, up to a maximum of 1,200 square feet.
    • Junior ADUs (JADUs), which are created within the existing walls of a single-family home, are limited to 500 square feet and must include a separate entrance and a small kitchen.

Height limits, lot coverage, and setbacks may further affect the size and placement of your ADU—especially in hillside areas or neighborhoods with architectural guidelines like The Oaks, Westridge, or Mulholland Heights.

At All Exclusive Construction, we evaluate your property and help you design an ADU that meets Calabasas regulations while maximizing your available space.

In Calabasas, setback and height requirements for ADUs vary depending on the type of ADU and your property’s zoning. However, the City generally follows California state law with some local adjustments:

Setbacks:

    • Detached ADUs must be set back at least 4 feet from rear and side property lines.
    • Attached ADUs must follow the same setbacks as the main dwelling, which may vary by zoning district.
    • ADUs built above garages or in hillside areas may require greater setbacks or special review.

Height Limits:

    • A one-story detached ADU is typically limited to 16 feet in height.
    • ADUs located above existing structures (like a garage) or in special overlay zones may be allowed up to 25 feet, depending on local planning review and neighborhood context.
    • Hillside lots or view-sensitive areas—such as those in Calabasas Highlands, The Oaks, or Mountain View Estates—may face stricter height limitations or design review requirements.

Before starting your project, it’s important to confirm the exact requirements for your parcel. At All Exclusive Construction, we handle the research, planning, and approvals needed to ensure your ADU fully complies with Calabasas setback, height, and zoning rules.

One parking space is required for an ADU unless it meets certain exemptions, such as being within a ½ mile walking distance of public transit, being part of the primary structure, or having no bedrooms. JADUs do not require additional parking, but if a JADU replaces a garage, that parking must be replaced on site.

An ADU may be rented separately from the primary residence but cannot be sold separately. ADUs cannot be rented out for less than 30 days. JADUs must be owner-occupied (either the JADU or main home) and require a deed restriction to be recorded before a building permit is issued.

Up to one ADU is permitted per single-family residential property. A JADU may also be permitted on a lot zoned for single-family residences if specific requirements are met. For lots with multiple family dwellings, additional regulations apply.

You can find detailed information about ADU and JADU construction in Calabasas on the official City of Calabasas website, specifically under the Building & Safety Division and Planning Division sections. These pages provide access to current zoning codes, development standards, permit application forms, and city-specific ADU guidelines.

Here are some useful resources:

At All Exclusive Construction, we stay up to date on Calabasas zoning regulations and handle all the necessary research, paperwork, and coordination with city officials so you don’t have to. If you have questions or want a site-specific assessment, we’re happy to walk you through it during a consultation.

These prices are only ball park figures to give you a rough idea as to what you should expect for the cost of design/build ADU construction project completed by a team of craftsman.  If you need a firm price please request a consultation so we can view your potential project, listen to your ideas, and determine the actual scope of work required to complete your ADU project.

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