California’s 2026 legislative session is entering its final stretch. Several proposals now approaching floor action could materially affect how architects, owners, and developers evaluate accessory dwelling units, density-bonus projects, and infill sites.
The important caution is that these measures were not yet law as of August 24, 2026. The Legislature’s deadline to pass bills is August 31, followed by a September 30 deadline for gubernatorial action. They belong in early feasibility studies and scenario testing—not yet in definitive client guidance.
The practical takeaway: test the opportunities now, preserve the assumptions, and wait for final chaptered language before changing standard project advice.
1. A New Formula for ADU Impact Fees
PendingSB 1117 passed the Assembly on August 20 and awaited Senate concurrence in Assembly amendments. The proposal would change impact-fee calculations for up to two ADUs on a lot. For an ADU larger than 750 square feet, fees would apply only to the area exceeding 750 square feet—not to the unit’s entire floor area.
A 1,000-square-foot ADU, for example, would have only 250 square feet of chargeable area under the proposed formula. That could materially improve the feasibility of the 800-to-1,200-square-foot units that are often large enough for family use but currently cross a meaningful fee threshold. Small ADUs already within the existing 750-square-foot exemption would see no direct change.
What to test now: add a “chargeable ADU area” field to preliminary fee models using max(ADU area − 750 sf, 0), clearly marked as prospective. See the official SB 1117 bill record.
2. Two Detached ADUs on a Single-Family Lot
PendingAB 956 remained on the Senate third-reading file. It would require ministerial approval of two detached new-construction ADUs on a lot containing an existing or proposed single-family dwelling, with each unit potentially limited to 800 square feet. A jurisdiction would not also have to allow a JADU when the two detached units are constructed.
If enacted, this could become a significant alternative to SB 9: an existing house plus two detached units, without a parcel map and without several of the eligibility constraints associated with an SB 9 urban lot split. The best path will still depend on site access, fire requirements, utilities, setbacks, and the owner’s long-term disposition strategy.
What to test now: compare “existing house + two detached 800-square-foot ADUs” with SB 9 and conventional ADU/JADU scenarios on representative Los Angeles-area lots. Review the official AB 956 bill record.
3. A Different Way to Calculate Density Bonus
PendingAB 2433, amended August 20, could allow applicants that provide a qualifying base-density study to elect an FAR-based density-bonus calculation instead of relying solely on dwelling units per acre. It would also more expressly characterize density bonuses, incentives, concessions, and waivers as nondiscretionary and not subject to separate CEQA review.
The FAR election matters because zoning density and the permitted building envelope do not always point to the same project yield. On some Los Angeles-area sites, the ability to demonstrate base density through FAR could unlock a materially different development program.
What to test now: run parallel studies using both units-per-acre and permitted-FAR assumptions, and retain the site and zoning evidence supporting each calculation. Review the official AB 2433 bill record.
4. Labor Standards and Buildings Over 85 Feet
PendingSB 1383 was amended on August 19 and August 21 and remained on the Assembly third-reading file. For buildings over 85 feet, qualifying locally adopted labor standards would be excluded from the development standards an applicant may seek to reduce or modify as a density-bonus incentive or concession.
The distinction is primarily financial. A project could retain density and dimensional benefits while losing a potential route for reducing certain locally imposed labor-cost requirements.
What to test now: identify applicable local labor standards early for any project approaching 85 feet, before treating all cost-increasing local requirements as concession-eligible. Review the official SB 1383 bill record.
5. Local Implementation Still Matters
State law may set the development pathway, but local implementation often determines the actual time and cost. Pasadena released a free 374-square-foot studio ADU standard plan updated to the 2025 California Building Code. It may reduce design and correction-cycle costs for a small detached unit, although site planning, utilities, fire access, setbacks, and fees remain project-specific. See Pasadena’s ADU Standard Plans Program.
Separately, HCD announced Prohousing Incentive Program awards for Culver City and Lancaster. These awards are funding decisions rather than direct entitlement changes, but they may support future local process improvements or housing programs worth monitoring. See HCD’s August award announcement.
What Has Not Changed
No consequential new SB 9 statute, HCD guidance, or significant published enforcement action appeared during the review period. HCD’s May 5 AB 2011 implementation guidelines also remained in draft form. For current projects, the prudent approach is to continue relying on enacted statutes and operative local procedures while identifying draft guidance as nonfinal.
The next meaningful checkpoint is the close of the legislative session. Once the final bill language and gubernatorial actions are known, feasibility tools, proposal assumptions, and client guidance can be updated with much greater confidence.
Project-specific review still matters. Housing statutes interact with zoning, fire access, utilities, title conditions, environmental constraints, and local procedures. This article is general information, not legal advice or a determination of development rights.