Background
SB 79 in depth
The fuller story behind the law — how stations qualify, the complete timeline, and the politics. The short version lives on the home page.
Which stations qualify
SB 79 sorts train stations into two groups, depending on how much train service they get. Busier stations get bigger required apartment sizes nearby.
- Top group ("Tier 1"): heavy-rail systems (BART, the LA Metro B and D lines), or "very high frequency" commuter rail — meaning at least 72 trains stopping per weekday, counting both directions. All three Palo Alto Caltrain stations land here — see how we counted.
- Second group ("Tier 2"): light rail (San Francisco Muni Metro, San Jose VTA, Sacramento RT, San Diego Trolley, the LA Metro A, C, E, and K lines), commuter rail with 48–71 trains per weekday, or buses running in dedicated bus-only lanes.
What gets allowed near a top-group station
Within a half-mile walk of a top-group station, the city can't block apartment buildings that meet these minimum sizes. For Palo Alto, this means all three Caltrain stations — they all qualify (how we counted).
| Distance from station | Min allowed height | Min allowed density | About this many stories |
|---|---|---|---|
| Adjacent (within 200 ft) | 95 ft | 160 units / acre | ~9–10 |
| Within ¼ mile | 75 ft | 120 units / acre, FAR 3.5 | ~7 |
| Within ½ mile | 65 ft | 100 units / acre | ~5–6 |
Buildings taller than 85 feet have to use union-scale labor (the official term is "skilled-and-trained workforce" or prevailing wage). And the city can submit its own plan to the state that moves where the new homes go — but only if the city's plan still allows the same total number of new homes overall.
Timeline
- January 2025SB 79 introduced by Sen. Scott Wiener.
- Spring & summer 2025Lawmakers add affordability requirements, union-scale labor for buildings over 85 feet, and a path letting cities submit their own plan instead.
- September 2025Passes both chambers of the legislature.
- October 10, 2025Signed into law by Gov. Gavin Newsom.
- January 1, 2026Cutoff: new train routes or extensions started after this date won't count toward SB 79 unless they'd qualify in the top group.
- March 20, 2026California's housing department clarified the rules — including that Caltrain counts as commuter rail, and that each station's group is set by counting trains per weekday (we counted Palo Alto's three).
- May 4, 2026The Palo Alto City Council was scheduled to discuss its SB 79 response, but the item was deferred late at night because earlier items ran long.
- June 1, 2026Palo Alto's Council passed the first reading of its own interim rules 5–0 — an exemption for historic properties, plus a rezone that allows half of SB 79's building size on transit parcels until about 2032. Full recap on Council watch.
- June 15, 2026Second reading passed; temporary ordinances take effect July 16. Urgency ordinances were not adopted, so the full state minimums apply in Palo Alto July 1–16 before the city’s rules kick in.
- July 1, 2026 — in effectState minimums kick in automatically across Alameda, Los Angeles, Sacramento, San Francisco, San Mateo, Santa Clara, and San Diego counties — unless a city has adopted its own compliant version first.
- Mid-2026 →The Bay Area's regional planning agency (called ABAG/MTC) will publish an official map of which stations qualify in which group. The map is presumed correct unless someone proves otherwise. (Our independent count already shows Palo Alto's three Caltrain stations all qualify in the top group.)
- 2026 – ~2032Cities that submit their own plan to the state can get up to ~6 years to redirect where the new homes go — as long as the total number of new homes still adds up.
- ~2031 (7th housing-plan cycle)Rules also start applying to unincorporated areas of qualifying counties (the parts not inside any city).
- OngoingLawsuits are expected, mostly from cities arguing the state shouldn't be able to override their zoning.
Why July 2026?
The bill was signed in October 2025, but the law itself included a ~9-month gap before the state minimums actually kick in. Three reasons:
- Maps had to be drawn. Each region's planning agency (the Bay Area's is ABAG/MTC) has to publish a map showing which stations qualify in which group. The state housing department didn't even publish its detailed definitions until March 2026.
- Cities got time. Before July 1, a city can write its own version of the rules, or submit its own plan to the state, and use that instead of the state defaults. Palo Alto is using this window.
- It's how California housing laws usually work. Earlier laws like SB 9, SB 35, and AB 2011 all gave cities a similar grace period between signing and the date the rules took effect.
Who supports it, who pushes back
Housing advocates (like California YIMBY), transit groups, environmental organizations, and the building trades unions all pushed for SB 79 — arguing California needs millions more homes, and that putting them near train stations is the lowest-impact way to do it. Many cities and homeowner groups opposed it, pointing to local control, infrastructure capacity, and neighborhood character. The bill went through major changes in 2025 to address those concerns — without giving up the core idea that the state can override local zoning near transit.