How Permitting Works In Calabasas.
Calabasas refreshed its ADU ordinance in late 2024 to bring local rules in line with state law, which means qualifying projects are approved ministerially: no public hearing, no discretionary review. The city must act on a complete application within 60 days, and most permits are fully approved in three to four months.
There is no minimum lot size for an ADU here. Any residentially zoned lot with an existing or proposed primary home qualifies. The city posts its local requirements on the Calabasas ADU page, and the statewide floor every city must honor comes from Government Code Section 65852.2. Not sure your parcel qualifies? Check your lot and we will map it for you.
Size And Height Limits.
A detached ADU in Calabasas can be up to 1,200 square feet. The base height limit is 16 feet, rising to 18 feet if the lot sits within half a mile of a transit stop or holds a multifamily building, and up to 20 feet when the ADU's roof pitch matches the primary home. Detached units also have to respect a 30% rear yard coverage cap.
Attached ADUs can be 1,200 square feet or 50% of the main home's floor area, whichever is less, and may rise to 25 feet or the zoning height limit (25 feet applies in the Hillside Overlay Zone), with a two-story maximum. Junior ADUs are capped at 500 square feet and must be carved entirely out of the existing single-family home.
Where You Can Build And How Many Units.
ADUs are allowed across every residential zone in the city: RS, RM, RR, HM (Hillside Mountain), RC, PD, and even OS. The one exception is RMH mobile home park zones. Overlay areas like Old Topanga and Calabasas Highlands layer on extra objective standards, but projects that meet them must still be approved ministerially.
On a single-family lot you can add one detached or attached ADU plus one JADU inside the existing home. Multifamily lots can go much further: up to eight detached ADUs (never more than the number of existing units) plus interior conversion ADUs totaling up to 25% of the unit count. If you own multifamily property, see how Abodu handles multifamily ADU projects at scale.
Setbacks, Parking, And Design Standards.
New ADUs need 4-foot side and rear setbacks, and detached units typically need at least 10 feet of separation from the main house. Setbacks do not apply to conversions or rebuilds of existing structures, and flood zones may allow extra height to meet elevation standards.
Most new ADUs need one off-street parking space, which can be uncovered and sit in the driveway, even behind another car. Parking is waived near transit, in historic districts, near car-share locations, on permit-parking streets, or when the ADU is part of an existing structure, and garage conversions never trigger replacement parking. Design-wise, expect to match the primary home's roof pitch, materials, or style so the ADU reads as part of the property.
What It Actually Costs.
Custom site-built ADUs in California routinely exceed $250,000 before change orders, and hillside grading in Calabasas only widens the unknowns. Abodu is transparent published pricing: homes from $234,800 plus a published installation price, an expected all-in from $298,800, covering design, permits, the factory build, delivery, and installation. See how the process works, or hear it from homeowners on our testimonials page.