The Homework: September 23, 2026
Welcome to the September 23, 2026 edition of The Homework, the official newsletter of California YIMBY — legislative updates, news clips, housing research and analysis, and the latest writings from the California YIMBY team.
News from Sacramento
Many of our priority bills from this session are now on Governor Newsom’s desk, awaiting his signature. The Governor has until September 30th to sign or veto bills passed in the final days of session. If he doesn’t act by then, a bill automatically becomes law without his signature.
The following bills are awaiting his signature:
- SB 1116 (Caballero): Makes improvements to state housing law to lower costs and speed construction of smaller, lower-cost starter homes.
- SB 1014 (Grayson): Requires cities to disclose all infrastructure requirements — sidewalks, sewers, etc. — within 30 days of a housing application, and prohibits adding new requirements after permit application.
- AB 2074 (Haney): Streamlines construction of high-rise residential and mixed-use buildings near regional transit hubs in California’s largest cities. It also would study potential sources for state-backed loans that could lower the cost of construction for these projects.
- SB 1117 (Cervantes): Removes the financial penalty many jurisdictions impose on ADUs over 750 sq ft, lowering the cost to build them.
- AB 956 (Quirk-Silva): Allows homeowners to build up to two detached ADUs on a single-family lot.
- SB 677 (Wiener): Protects approved housing projects from local delay tactics over the creation of subdivisions and approval of federal financing for affordable housing.
We’ll keep you posted as the Governor acts on these bills over the coming weeks, and we’ll be back next year to keep taking action toward making California affordable for everyone.
Be sure to follow California YIMBY’s Twitter and Bluesky to get more up-to-date news on housing policy, legislation, and research. If you find this newsletter valuable, forward it to a friend.
Housing Research & Analysis
The Case for Filtering and Moving Chains: Evidence from Honolulu
Does building new housing lead to lower rents in older housing? A new study out of Honolulu tests that claim by tracking “moving chains” in a single building, The Central, a 512-home tower in Honolulu, completed in 2021.
Each older home a resident leaves behind to live in The Central – which includes 202 market-rate homes and 310 deed-restricted units – becomes available to someone else. Each subsequent vacancy triggers another vacancy down the price scale, in a process economists call “filtering.”
In “The Downmarket Impact of New Multifamily Housing: Evidence from a Honolulu Condo Tower,” researchers Limin Fang, Emi Kim, and Justin Tyndall trace the moving chains set off by The Central’s first residents, comparing what happens when market-rate and income-restricted homes get new occupants.
Key Takeaways:
- Steep Price Drops: The homes vacated in the first round of moves to The Central cost 38% less per square foot; homes vacated in the next round cost 44% less.
- Vacancy Rate Split: New market-rate homes generate more moves and vacancies per home (0.43) than income-restricted homes (0.29).
- Moving up: The Central’s first residents moved from neighborhoods with 15% lower median incomes, freeing up less-costly housing stock while also demonstrating the demand in higher-income neighborhoods.
How Local Politics Influence Housing Affordability
California needs at least 2.5 million new homes by 2030, but most cities are still falling short. A new study examines whether this shortfall is associated with the politics of who lives in these cities, and how those politics determine local governance.
In “Why Cities Resist New Housing: NIMBYism, Institutions, and Permitting Relative to Need,” researchers Robert W. Wassmer and Shoshana F. Levy analyzed eight years of permitting records from 478 California cities to uncover which resident traits and government structures are associated with more housing growth.
Key Takeaways:
- Housing Delays. Each additional 100 days a city takes to submit an approved housing plan to the state results in that city issuing 3.7% fewer permits for very-low-income housing, and 2.3% fewer total permits overall, over the 2015–2024 study period.
- Age Divide. Every 1% increase in a city’s population above age 55 is linked to about 3% fewer very-low-income permits. In contrast, each 1% increase in the population aged 25-34 is linked to 7% more very-low-income permits.
- Charter Advantage. Charter cities (which set their own local government rules) issued about 80% more very-low-income permits and 90% more low-income permits than comparable “General Law” cities of similar size, population, and wealth that default to state rules.
Houser Headlines
- A raft of California housing bills heads to Newsom; here’s what’s new
- The California condo is dying. Can this affordable housing option be saved?
- California must include Latino families in homeownership
- Why a bill to juice condo construction died even though California lawmakers voted for it
- A case for permit shot clocks builds as approval durations drag out
- 12-story SB 79 building pitched in Santa Monica
- With new leverage, builder pitches two plans for downtown Palo Alto housing project
- California tool to encourage low-income rentals may suppress new apartment construction
- CA cities hit with SB 79 lawsuits after allegedly dragging feet on transit-oriented development
- SANDAG wanted less housing by some train stations. Now it’s got a legal fight.
- The Bay Area is ‘exporting’ the housing crisis to the rest of the state, report finds
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