Home Addition Contractors & ADU Builders in Calabasas, CA

Building ADUs and additions in Calabasas

Calabasas is an incorporated city, not part of the City of Los Angeles, so its own Community Development Department reviews planning and building permits. Homeowners who assume LADBS rules apply here are usually surprised — Calabasas applies its own design standards on top of California's ADU baseline.

Two additional factors shape nearly every Calabasas project. First, many neighborhoods are governed by HOAs with architectural review committees that weigh in on massing, materials, and colors; California law limits how far an HOA can restrict an ADU, but the review process is still real and needs to run in parallel with the city submittal. Second, much of Calabasas sits in Very High Fire Hazard Severity Zones, which drives exterior materials, defensible space, and fire-access design.

Typical Calabasas work: a detached ADU or guest house on a larger hillside lot, an above-garage unit where the pad is limited, and substantial home or second-story additions on established homes.

Calabasas permitting — City of Calabasas, plus HOA review

Calabasas runs its own planning and building review through the City of Calabasas Community Development Department. Zoning, design standards, hillside rules, and submittal steps come from the city — LADBS Standard Plans and City of LA procedures do not apply.

A Calabasas mailing address alone does not establish city jurisdiction. For a parcel inside city limits, confirm addition plans with the city's Building and Safety and Planning divisions. An unincorporated parcel instead follows Los Angeles County Building and Safety and Regional Planning. Check the parcel's jurisdiction, zoning, setbacks, height and applicable site requirements before design; local rules and site conditions vary.

Where an HOA exists, its architectural review committee typically evaluates exterior design elements. We prepare submittals for both tracks so the HOA process does not become the bottleneck after the city has already reviewed the plans.

Site conditions that affect Calabasas projects

• Very High Fire Hazard Severity Zone requirements — exterior materials, vents, and defensible space.
• HOA architectural review running in parallel with city plan check.
• Hillside grading, retaining walls, and drainage on sloped parcels.
• Fire-department access, driveway width, and turnaround requirements.
• City of Calabasas design standards affecting massing, roof form, and materials.
• Utility routing and panel capacity on larger, spread-out sites.

Home addition types offered in Calabasas

Room additions can add a bedroom, office or family room; second-story additions build upward where the existing structure and local limits allow. A master suite combines sleeping, bath and closet space, while a kitchen addition grows the existing footprint. Explore our home addition design and construction services and Los Angeles County service area before choosing a layout.

Calabasas service deep dives

Calabasas neighborhoods we cover

Neighborhoods listed describe our coverage area, not project addresses.

Budgeting your Calabasas ADU or addition

Every number we publish is a preliminary planning range, not a quote. Cost in Calabasas moves with unit size, design complexity, site conditions, utility work, jurisdictional requirements, and finish level. Use our cost estimator to build a starting range, then we produce a detailed construction proposal after feasibility and design work is complete.

Calabasas ADU questions, answered

Nearby areas we build in

Further reading

• 2026 California ADU Guide
• California ADU setbacks
• Attached vs. detached ADU