SB 9 in Santa Barbara: Can You Split Your Lot or Build a Duplex in 2026?
California's landmark lot-split law is fully implemented in Santa Barbara — but with local rules, a coastal and fire overlay, and an open legal question that every homeowner should understand first.
By Johannes Steenkamp, Realtor® | Keller Williams Realty, Santa Barbara | Updated July 2026
The short version: SB 9 lets many single-family homeowners add a second unit or split their lot in two — potentially up to four units on what was one single-family parcel — through a streamlined, ministerial process. Santa Barbara adopted SB 9 back in 2022 and still processes applications today, but the City layers on notable requirements, including an affordable-housing condition and fire- and coastal-zone limits. There's also an unresolved court question about whether SB 9 fully applies to charter cities like Santa Barbara.
Few housing laws have changed the conversation around single-family property in California as much as Senate Bill 9. For Santa Barbara homeowners sitting on a well-located single-family lot, it raised a tempting question: could you add a unit, split the land, and unlock real value? The answer here is a qualified "yes" — with important local details that make Santa Barbara different from many other California cities. Here's how SB 9 actually works in our area.
What Is SB 9?
SB 9, known as the California HOME Act, took effect in 2022. In single-family residential zones, it does two main things:
Two-unit development. It allows up to two primary units on a single-family lot — as a duplex, or as two detached homes — where typically only one was allowed.
Urban lot splits. It allows a qualifying single-family lot to be divided into two lots, each generally at least 1,200 square feet, with the split no more lopsided than roughly 40/60.
Combine the two, and a single parcel can potentially support up to four units. The key feature is ministerial approval: qualifying projects skip discretionary review and public hearings, and are approved by staff against objective standards. Local governments can apply objective zoning, subdivision, and design standards — but only to the point that they don't physically prevent building the units.
How Santa Barbara Handles SB 9
The City of Santa Barbara implemented SB 9 through amendments to its Municipal Code, effective January 2022, and continues to process two-unit and urban-lot-split applications. A few things stand out about the local approach:
Where it applies. SB 9 is available in the City's single-unit residential zones (the RS zones, and A, E, and R-1 in the Coastal Zone). It does not apply in R-2, multi-unit, or commercial, office, and manufacturing districts.
An affordability requirement. This is the big one. Santa Barbara's ordinance requires at least one unit in a two-unit development — or at least one unit on a lot created by an urban lot split — to be offered for sale or rent as a moderate-, low-, or very-low-income unit. In the Coastal Zone, that unit is limited to low-income affordability. This condition meaningfully shapes the economics of an SB 9 project here.
Ministerial, if you meet the standards. Projects consistent with the City's objective zoning, subdivision, and design standards are processed ministerially, without discretionary hearings.
It's worth being candid: Santa Barbara is widely regarded as one of California's more restrictive cities on SB 9 implementation. That doesn't mean projects can't pencil out — it means the details matter enormously.
The Charter-City Question: Is SB 9 on Solid Ground in Santa Barbara?
Here's a nuance most homeowners don't know. The City of Santa Barbara is a charter city, which under California's "home rule" doctrine has constitutional authority over its own municipal affairs. In 2024, a Los Angeles trial court ruled that SB 9 was unconstitutional as applied to a group of charter cities that had sued the state. That ruling was binding only on those specific petitioner cities — Santa Barbara was not a party — so SB 9 has remained in effect here.
Since then, the picture has kept evolving. A separate appellate decision upheld SB 9 as applied to general-law cities, the Legislature amended the law to clarify its affordable-housing purpose, and in early 2026 an appellate court sent the charter-city case back to the trial court to reconsider in light of that clarification. In short: the question of how SB 9 ultimately applies to charter cities is still unsettled, and Santa Barbara continues to implement the law while the courts work through it. If you're planning an SB 9 project, this is a moving target worth confirming with the City before you invest.
SB 9 Beyond the City: County, Montecito, Goleta & the Santa Ynez Valley
"Santa Barbara" means different jurisdictions depending on where your property sits, and SB 9 plays out a little differently in each:
Unincorporated Santa Barbara County (including Montecito and much of the Santa Ynez Valley) adopted its own SB 9 ordinance. When the law arrived, County planners estimated that tens of thousands of unincorporated properties could potentially qualify.
Goleta, a general-law city, also adopted objective standards to implement SB 9. Because the courts have upheld SB 9 for general-law cities, its footing there is more settled than in a charter city.
Coastal-zone properties across all of these areas carry an extra layer of review and, often, additional conditions.
What SB 9 Could Mean for Santa Barbara Homeowners
Used well, SB 9 opens doors that single-family zoning historically kept shut:
Add a second home on your lot for rental income or family — separate from the ADU pathway.
Split your lot and potentially sell or develop the second parcel, unlocking equity from land you already own.
Create multigenerational flexibility — a real draw in a market where housing for adult children or aging parents is scarce.
Increase long-term property potential in a supply-constrained, high-value area.
The catch, locally, is that Santa Barbara's affordability requirement and overlay rules can change the math quickly. Whether SB 9 is the right move depends heavily on your specific lot, zone, and goals.
Key Limits to Know
Fire zones. In the City, SB 9 is prohibited in the Foothill and Extreme Foothill High Fire Hazard Areas, and projects in other high-fire areas face added requirements like fire sprinklers and parking limits.
Coastal Zone. Expect additional review and conditions, including stricter affordability terms.
No short-term rentals. Units created under SB 9 can't be rented for terms under 30 days.
Owner-occupancy for lot splits. An urban lot split generally requires the owner to intend to occupy one of the units for a set period.
Objective standards still apply. Setbacks, height, and design standards remain in force, so a "by-right" project still has to fit the rules.
A local reality check: SB 9 is powerful, but in Santa Barbara it comes with real conditions and an unresolved legal backdrop. Before you spend money on plans or a survey, confirm your property's zone and eligibility with the City or County planning department, and get clear on the affordability requirement — it's the factor most likely to change whether a project makes sense.
Frequently Asked Questions
Can I use SB 9 to split my lot in Santa Barbara?
Potentially, yes, if your property is in an eligible single-family residential zone and meets the City's objective standards. Santa Barbara implemented SB 9 in 2022 and still processes urban lot split applications, though local conditions — including an affordability requirement — apply.
How many units does SB 9 allow?
SB 9 allows up to two primary units on a single-family lot, and it allows an eligible lot to be split into two. Combined, that can mean up to four units on what was originally one single-family parcel.
Does SB 9 really apply to Santa Barbara if it's a charter city?
For now, yes — the City continues to implement SB 9. A 2024 court ruling found SB 9 unconstitutional as applied to certain charter cities that sued the state, but Santa Barbara wasn't a party, and as of early 2026 that case was sent back for reconsideration after the Legislature clarified the law. The charter-city question remains unsettled, so confirm current status with the City.
What's the affordability requirement for SB 9 in Santa Barbara?
The City's ordinance requires at least one unit in a two-unit development, or on a lot created by an urban lot split, to be offered as a moderate-, low-, or very-low-income unit. In the Coastal Zone, that unit is limited to low-income affordability.
Can I build an SB 9 project in a fire hazard area?
Not in the City's Foothill and Extreme Foothill High Fire Hazard Areas, where SB 9 is prohibited. In other high-fire areas it may be allowed with additional requirements such as fire sprinklers and parking restrictions.
Wondering If Your Santa Barbara Property Qualifies for SB 9?
Every lot is different, and the local rules make all the difference. I'm always glad to talk through what your specific property might allow — no pressure, just a clear, honest conversation about your options and goals.
Johannes Steenkamp, Realtor® — Keller Williams Realty, Santa Barbara
📞 805-886-6581 | ✉️ jsteenkamp@kw.com
🌐 www.johannessteenkamp.com | CalDRE# 02057072 · SFR · SRES
This article is provided for general information only and is not legal, tax, or construction advice. SB 9 rules, local ordinances, and pending litigation change over time; please confirm current requirements and your property's eligibility with your city or county planning department and the appropriate licensed professionals before making decisions.