The short version
On September 30, 2026, Governor Gavin Newsom signed SB 1090, which its author calls the "Keep Altadena Land in Altadena Hands Act." Since October 1, it has paused one state fast track, SB 1123, in Altadena's two ZIP codes, 91001 and 91003. SB 1123 lets an owner divide a vacant single-family lot into as many as 10 homes without a public hearing. The pause lasts until January 1, 2030.
The pause is narrower than many people expect. SB 9 lot splits and duplexes, ADUs, fully affordable projects and SB 1123 applications filed before October 1 can all go ahead. For most Altadena owners, the county's like-for-like rebuild rules matter more, and SB 1090 does not change them.
Below is the background: the fire, the laws involved, who pushed for the pause, how it changed on the way to the governor, and what it means if you list or sell in Altadena.
How Altadena got here: the Eaton fire
The Eaton fire started at 6:18 p.m. on January 7, 2025, the same day as the Palisades fire, and was contained on January 31. LA County's fact sheet puts the toll at 14,021 acres burned, 9,414 structures destroyed, 1,074 damaged and 19 deaths.
Altadena took the heaviest losses. It is an unincorporated community, so LA County, not a city, handles its planning and permits. County permit data reviewed by The Real Deal counts 5,858 Altadena parcels where a home was completely destroyed.
The damage fell unevenly. Research from UCLA's Latino Policy and Politics Institute, summarized by USC Dornsife, found that about 61% of Altadena's Black households were inside the fire perimeter.
Rebuilding has been slow. Seven months after the fire, the same research found that about 70% of severely damaged homes showed no rebuilding activity, and that investors had bought about two-thirds of the homes that sold. The Real Deal's review this fall found that more than 2,300 of the 5,858 destroyed-home parcels, about 40%, still had no rebuild application.
That mix of empty lots, owners still deciding what to do and investors buying is the backdrop for SB 1090.
The two state laws at the center: SB 9 and SB 1123
California has passed several laws that make it easier to add homes in single-family neighborhoods. Two matter in Altadena.
SB 9 lets a homeowner split a single-family lot or build a duplex through ministerial approval, meaning staff sign off if the project meets objective rules. An owner who splits a lot must commit to living on the property for three years. That requirement makes SB 9 hard for an outside investor to use.
SB 1123 took effect on July 1, 2025. It expanded SB 684, a 2023 law that requires cities and counties to approve small subdivisions of up to 10 lots or homes ministerially, with no CEQA environmental review, no public hearing and no appeal. SB 1123 extended that fast track to vacant lots zoned for single-family homes. Lots in high or very high fire hazard severity zones are excluded, according to LA City Planning's summary of the law.
The fire turned thousands of Altadena home sites into vacant lots, which made SB 1123 newly relevant. In principle, a buyer could purchase a burned lot and divide it into as many as 10 homes with no hearing. Residents and county officials worried that speculators would do that at a density the neighborhood's roads and utilities were not planned for.
Who is behind SB 1090, and why
State Senator Sasha Renée Pérez (D-Pasadena) wrote the bill. LA County Supervisor Kathryn Barger sponsored it, according to a county legislative report. The county's Department of Regional Planning supported it, saying a pause would give county departments time to plan infrastructure for added density and let rebuilding follow the pattern the neighborhood had before the fire.
Pérez framed the pause as time for survivors. "By creating a 3-year moratorium on SB 1123, Eaton Fire survivors will have the time they need to rebuild without the undue influence of real estate speculators," she said in a statement reported by CBS Los Angeles.
How the bill narrowed before it passed
Earlier drafts went further. A June draft described in the county's legislative report would have paused both SB 9 and SB 1123 for applications filed from January 7, 2025 through January 7, 2030. Pasadena Now reported that one version proposed a five-year moratorium on both laws.
The final law is narrower in three ways:
- It covers SB 1123 only. SB 9 stays available.
- It applies to applications filed on or after October 1, 2026, not back to the date of the fire.
- It exempts projects that are 100% affordable. Pérez said affordable housing developers supported keeping that exemption.
In his signing message, Newsom wrote that housing streamlining laws remain essential to addressing the state's shortage, and that any adjustments for extraordinary recovery situations should be narrowly tailored.
One criticism is timing. The pause starts about 21 months after the fire. By then, by the UCLA research's count, investors had already bought about two-thirds of the homes that sold in the first seven months.
What the pause does not cover
- SB 9 projects. Lot splits and duplexes remain available.
- ADUs. Accessory dwelling units are allowed by right under state law and are not part of the pause. Pérez has said more than half of the people rebuilding are adding an ADU.
- Fully affordable projects. 100% affordable SB 1123 projects can still use the fast track.
- Earlier applications. SB 1123 applications submitted before October 1 remain valid. The filing date decides, not whether the project had vested rights.
- Like-for-like rebuilds. These follow the county's own rules, explained below.
Why like-for-like rebuilds move faster, and why they can be a little bigger
LA County defines a like-for-like rebuild as a structure of generally the same size, location and purpose as the one that was lost. Because the county is approving something that already stood on the lot, it can skip much of the review a new design needs.
- Streamlined review. Like-for-like plans get streamlined land-use review. Pasadena Now reported the county's commitment to an initial plan review within 10 business days and rechecks within five.
- Old setbacks can stay. A like-for-like rebuild can keep existing nonconformities, such as setbacks that do not meet current zoning. Without that rule, many older homes could not go back on the same footprint.
- State environmental review waived. Executive Order N-4-25, signed by Newsom in January 2025, suspended CEQA and California Coastal Act permit requirements for rebuilding in substantially the same location, as long as the new structure does not exceed 110% of the original footprint and height.
Why can a rebuild be larger? The county allows a limited increase so owners can make modest changes without losing the fast track. In the Eaton fire area, a rebuild can be up to 10% or 200 square feet larger, whichever is greater. In the Palisades fire area, the limit is 10%. The 200-square-foot floor matters for small homes: on a 1,000-square-foot house, 10% would be only 100 square feet. The 10% allowance also roughly matches the state order's 110% limit for skipping environmental review.
Limits to know:
- A home larger than the like-for-like allowance is reviewed under the Altadena Community Standards District, which requires a front yard of at least 20 feet.
- Homes on septic systems must keep the same number of bedrooms.
What happens next
- The pause ends January 1, 2030. After that, SB 1123 applies in Altadena again unless lawmakers extend or change it.
- Longer-term growth goes to corridors. The West San Gabriel Valley Area Plan, approved weeks before the fire, steers new density toward commercial corridors such as Lincoln Avenue rather than single-family streets.
- Rebuild pace is the number to watch. About 40% of fully destroyed parcels still lack an application. How many of those owners rebuild, sell or hold will drive Altadena's inventory over the next few years.
What this means for LA agents
- Price vacant lots on what is allowed now. For applications filed after October 1, a buyer cannot use SB 1123 to plan up to 10 homes before 2030. Lot value rests on a like-for-like rebuild, an SB 9 split or duplex, and ADUs.
- Check the application date. A lot with an SB 1123 application filed before October 1 keeps that path. Get the filing records and make them part of the listing.
- Know the like-for-like math. Buyers who want a fast rebuild can add up to 10% or 200 square feet. Anything bigger goes through the Altadena Community Standards District.
- Flag the SB 9 owner-occupancy rule for investors. A lot split requires a three-year commitment to live on the property.
- Send parcel questions to the county. Fire hazard zone, septic status and permit history vary by lot. LA County Planning is the source of record.