Newsom weighs AB 956 and SB 1117 as California ADU bills hit the Sept. 30 deadline

Homeowners and builders tracking California accessory dwelling unit (ADU) policy are watching Sacramento this week: Assembly Bill 956 and Senate Bill 1117 are enrolled and sitting on Governor Gavin Newsom’s desk, with a hard action deadline of September 30, 2026, according to California Legislative Information bill-status records.

Neither measure appeared on Newsom’s September 27, 2026, legislative update. As of research on September 28, 2026 (PT), both remain pending — so sign, veto, or possible inaction that lets a bill become law without a signature are all still open under the state’s end-of-session rules.

What AB 956 would change

AB 956, authored by Assemblymember Sharon Quirk-Silva, would raise the number of detached, new-construction ADUs that a local agency must ministerially approve on a lot with a proposed or existing single-family dwelling from one to two, according to the enrolled bill text and Legislative Counsel’s Digest on California Legislative Information.

The measure would also amend Civil Code rules that make certain covenants, restrictions, and governing-document provisions void and unenforceable when they effectively prohibit or unreasonably restrict a compliant ADU or junior ADU (JADU). The enrolled text shifts that protection from lots “zoned for single-family residential use” to lots “zoned to allow single-family residential use” — language advocates say closes denial pathways cities have used when a single-family house sits on a multi-family-zoned parcel (Bay Area ADU Manager, Sept. 1, 2026; AB 956 enrolled text).

One limit: a local agency would not be required to ministerially approve a JADU on the same lot where two detached new-construction ADUs have already been built under the expanded path (AB 956 enrolled text, Sec. 66323).

What SB 1117 would change on impact fees

SB 1117, authored by Senator Sabrina Cervantes, targets ADU impact-fee math. Under current state rules, ADUs of 750 square feet or less are generally exempt from impact fees, while larger units can be charged proportionally against the primary dwelling. The enrolled bill would require that fees on an ADU with more than 750 square feet of interior livable space be charged only on the area in excess of 750 square feet — not on the full unit once that threshold is crossed (SB 1117 enrolled text amending Government Code § 66311.5; HousingWire, Aug. 31, 2026).

That could shrink the fee base for larger units, though the dollar impact still depends on each city’s schedule. Some jurisdictions already waive or defer ADU fees; elsewhere, the overage-only math could be material (Bay Area ADU Manager, Sept. 1, 2026).

How the bills reached the Governor’s desk

Both measures cleared the Legislature near the end of the 2025–2026 regular session and were presented as enrolled bills:

• SB 1117 — Enrolled and presented to the Governor at 6 p.m. on August 30, 2026; House Location: Governor (California Legislative Information). SB 1117 status
• AB 956 — Enrolled and presented to the Governor at 4 p.m. on September 4, 2026; House Location: Governor (California Legislative Information). AB 956 status

LegInfo concurrence history shows Assembly concurrence on AB 956 at 60–2 (Aug. 27, 2026) and Senate concurrence on SB 1117 at 38–0 (Aug. 25, 2026). Strong margins do not guarantee a signature; Newsom has returned other 2026 measures without signature this month.

HousingWire reported at session’s end that the two bills were part of a broader housing package headed to Newsom covering ADUs, fees, permitting timelines, and density — continuing years of state ADU preemption aimed at making backyard units easier and cheaper to build (HousingWire, Aug. 31, 2026).

Why it matters for California homeowners and builders

If enacted, most projects would not feel the change in this fall’s permit queue. Non-urgency bills enacted in this window generally take effect January 1, 2027; secondary reporting notes bills enacted on or before October 2 take effect then (Bay Area ADU Manager, Sept. 1, 2026). Applications filed under today’s rules would still face today’s one-detached-unit path and fee math until the new statutes apply.

For homeowners, AB 956 would expand lot-level capacity and tighten state limits on HOA and deed restrictions that block compliant ADUs. Builders and designers may ask whether site plans should leave room for a second detached unit if the bill becomes law — without treating that second unit as locked in before the Governor acts. For fee-sensitive projects above 750 square feet, SB 1117 would change the spreadsheet more than the site plan.

Neither bill is a blanket entitlement. Coastal Local Coastal Programs, fire-hazard rules, and local objective standards still authorized under state ADU law can shape what gets built — separate from the questions now before the Governor.

Looking ahead: what happens by Sept. 30

Newsom has until September 30, 2026, to sign or veto end-of-session bills. Outcomes for AB 956 and SB 1117 remain unsettled as of September 28, 2026 (PT):

1. Sign — bills become law (effective Jan. 1, 2027 if enacted in this window).
2. Veto — bills die unless the Legislature overrides (rare for end-of-session measures).
3. No return by the deadline — under California’s Art. IV pocket-approval practice for bills passed before September 1 and not returned by September 30, a measure can become law without the Governor’s signature (Homes by Clearway, Sept. 2026, summarizing constitutional practice).

Until an official action appears on LegInfo or a Governor’s legislative update, treat both ADU bills as pending — not as settled 2027 law. Watch California Legislative Information status pages and the Governor’s bill-action releases after September 30.

Quick Tip: If you’re planning an ADU this fall, confirm your city’s current ADU impact-fee schedule and detached-unit limits before locking drawings — and ask your designer whether a one-detached layout can flex to a second unit later if AB 956 takes effect January 1, 2027. Treat HOA CC&Rs and coastal or fire-zone overlays as separate checks; a Governor signature does not rewrite those site constraints overnight.

Xavier Rodriguez is the CEO of ADU Geeks, San Diego’s leading ADU consulting and project management firm. In 2024, the company was ranked No. 1 on the San Diego Business Journal’s Fastest Growing Private Companies list in the Small Business category, achieving 594.3% revenue growth.

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