Santa Clarita ADU Rules After Ordinance 26-2: What Changed in 2026

Santa Clarita no longer applies its own setback, parking, design or fire-zone rules to the accessory dwelling units that state law requires it to approve. What remains are the size and height caps the state statute itself lets a city impose. The City Council adopted Ordinance No. 26-2 on April 28, 2026, by a 4 to 1 vote, after the California Department of Housing and Community Development found the earlier ordinance out of compliance with state ADU law. Section 17.57.040(L) of the municipal code now points to Government Code section 66323 and says state law controls where the two conflict. For a lot inside city limits, the statute now sets the development standards, and the city code keeps provisions on fees, utility connections, addresses and occupancy certificates.

What Did the State Find Wrong With Santa Clarita's ADU Ordinance?

HCD reviewed Ordinance No. 25-1, which the Council had adopted on May 27, 2025, and sent written findings on December 10, 2025. The letter lists 12 numbered ADU findings and 10 more on the city's separate two-unit (SB 9) ordinance. The ordinance required owner occupancy for any ADU applied for on or after January 1, 2025, an allowance the Legislature had already removed. It required replacement parking when a junior ADU went into an attached garage. It also asked that the unit's architecture be "compatible" with the main house, a subjective standard that HCD said state law does not permit.

It was the second such letter. HCD's March 24, 2023 findings on the original 2021 ordinance had already objected to the fire-zone, oak tree and Significant Ecological Area provisions listed in the table below.

What Did Ordinance 26-2 Change?

The agenda report for the April 14, 2026 first reading describes the change. Staff wrote that the state-mandated units "must be allowed under state law" regardless of any local development or design standard, and that the city will no longer be able to restrict ADUs and junior ADUs in high fire zones, under the oak tree preservation ordinance, or because of proximity to a Significant Ecological Area. The Council adopted the ordinance at second reading on April 28; the minutes record the result as "Adopted Ordinance No. 26-2". Section 8 of the ordinance makes it effective 30 days after adoption.

Earlier city rule	Where it was challenged	Current city position
ADU prohibited in a high fire hazard severity zone unless highway-access conditions were met	HCD letter, March 24, 2023	City staff report: fire zones can no longer be a basis to restrict these units
Oak tree ordinance and SEA overlay applied to ADUs	HCD letter, March 24, 2023	Same staff report: no longer a basis to restrict these units
Owner occupancy for ADUs applied for from January 1, 2025	HCD letter, December 10, 2025, finding 9	Code keeps owner occupancy only for junior ADUs, with a state-law exemption
No detached ADU on a lot with an attached ADU	HCD letter, December 10, 2025, finding 11	City handout for single-family lots: an owner may have each type; multifamily lots are referred to Planning
Replacement parking for a junior ADU in an attached garage	HCD letter, December 10, 2025, finding 6	City handout: no parking requirements for ADUs or junior ADUs

What Can a Santa Clarita Homeowner Build Now?

For a lot in a residential or mixed-use zone with one existing or proposed single-family home, Government Code section 66323 requires ministerial approval of three unit types, in any combination. The Planning Division's ADU handout summarizes them, with slightly different wording on transit distance and roof pitch:

Unit type	Size	Setbacks	Height
Conversion of part of the house or an existing accessory structure, with exterior access	No maximum; up to 150 sq ft of expansion for ingress and egress on an accessory structure	Enough for fire and safety	Not applicable
Detached, new construction	City caps at 800 sq ft of livable space, as section 66323(a)(2)(A) allows	4 feet, side and rear	16 feet; 18 feet near qualifying transit, plus 2 feet to match the main roof pitch
Junior ADU inside the house or attached garage	Up to 500 sq ft	Enough for fire and safety	Not applicable

The height figures come from section 66321, subdivision (b)(4). The 18-foot allowance applies within one-half mile walking distance of a major transit stop or high-quality transit corridor. Section 66323(b) bars the city from adding any objective development or design standard that the section itself does not authorize.

Can the City Still Charge Fees or Limit Rentals?

Yes on both. Under Government Code section 66311.5, subdivision (c), no impact fee may be charged on an ADU with 750 square feet of interior livable space or less, or on a junior ADU of 500 square feet or less. Above 750 square feet, fees must be proportionate to the square footage of the primary dwelling. The exemption covers impact fees only. Under subdivision (c)(2), connection fees and capacity charges are a separate matter, and the city code also keeps permit and inspection fees.

Rental terms are fixed in the other direction. Section 66323(e) requires a rental term longer than 30 days for these ADUs, and section 66333(g) does the same for junior ADUs. The municipal code states the rule as 30 days or longer for both. An ADU may be rented separately from the house, but the handout states it cannot be sold or conveyed separately. A junior ADU that shares a bathroom with the main house still requires the owner to live in one of the two, under section 66333, subdivision (b), unless the owner is a governmental agency, land trust or housing organization. Subdivision (c) calls for a recorded deed restriction that bars separate sale of a junior ADU; confirm with Planning how the city applies it.

How Long Does Santa Clarita Have to Decide an ADU Application?

Section 66317 sets two clocks. The city has 15 business days to say whether an application is complete, and 60 days from a completed application to approve or deny it when the lot already has a dwelling. If neither happens within 60 days, the statute says the application "shall be deemed approved". The clock stops for any delay the applicant requests, and an ADU filed together with a new house can wait for the house permit. A denial has to arrive within the same period with a written list of defects.

What Do Fire Zones and Oak Trees Still Mean for an ADU?

The location ban is gone. The building code is not. HCD's 2023 letter noted that projects in high fire hazard severity zones must still meet the stricter standards of Chapter 7A of the California Building Code.

The staff report says the oak ordinance can no longer be used to restrict these units, and in the same paragraph adds that residents remain responsible for impacts to protected species. The report does not spell out what that means for removing a protected oak to clear a building pad. Put that question to the planner on a specific site plan. The general permit thresholds are in Santa Clarita oak tree permit rules.

What Should a Buyer Verify Before Paying for ADU Potential?

One number deserves a direct question to the Planning Division. The city handout lists 800 square feet as the maximum for a detached ADU, which is the cap section 66323 lets a city impose on the units it must approve regardless of local rules. Government Code section 66314, subdivision (d)(5), separately sets 1,200 square feet as the ceiling for a detached ADU under a local ordinance written to that section. The handout does not say whether Santa Clarita will process a detached unit between those two figures, or under which standards.

Check	Why it matters
Confirm the lot is inside city limits	Unincorporated areas such as Stevenson Ranch and Castaic follow Los Angeles County code, not Ordinance 26-2
Ask Planning in writing whether a detached ADU over 800 sq ft is accepted	The handout and section 66314 give different ceilings
Price the plan at 750 sq ft and at the size you want	Impact fees start above 750 sq ft of interior livable space; connection and permit fees are separate
Ask whether the lot is in a high or very high fire hazard severity zone	Chapter 7A construction standards still apply
Measure any existing accessory structure	The handout sets no maximum area for a conversion, so the existing dimensions, plus up to 150 sq ft for ingress and egress, define the unit

The city-versus-county question is covered in Santa Clarita city limits vs unincorporated LA County. A seller with a permitted ADU, or with room for one, can ask for a home valuation that accounts for it, and buyers weighing lots on this basis can start with what to check when buying.

Q: Does the 2026 ordinance apply to an ADU application filed before it took effect?

Ordinance 26-2 was adopted April 28, 2026, and took effect 30 days later. The documents reviewed here do not say how applications pending on that date are handled. Ask the Planning Division which version of section 17.57.040 governs a specific file.

This article is general information about City of Santa Clarita ordinances and California housing law, not legal or land use advice. Ordinance text, fee schedules and state statutes change. Confirm current requirements with the Santa Clarita Planning Division before relying on any figure here. Call Alla at (818) 699-5367 or use the enquiry form.

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