California's New 2026 Housing Laws: What Homeowners and Contractors Need to Know

On September 29, 2026, Governor Gavin Newsom signed a new package of housing bills aimed at making California homes faster and cheaper to build. Most of the changes take effect January 1, 2027. Here is what they mean for homeowners planning a remodel, an ADU or a rebuild, and for the contractors who build them.

Key Takeaways

• Cities can require no more than two plan check rounds for a building permit (AB 1621).
• Post-entitlement permit decisions are due in 30 days for projects of 25 units or fewer, and 45 days for larger ones (AB 1621).
• Cities must list required infrastructure improvements early and cannot add new ones later without specific findings (SB 1014).
• Townhome and small-lot projects get easier approval paths (AB 1751, SB 1116).
• ADU rules shift on impact fees and the number of detached units (SB 1117, AB 956).
• Rules vary by city and parcel, so confirm your property's rights before you design.

Fewer Permit Delays: AB 1621

For years, plans came back with a new round of comments after every resubmittal. AB 1621 caps plan checks and specification reviews at two per building permit application. After the second submittal, the city may deny the application, but the applicant can reapply. The bill also shortens how long an agency has to act on a post-entitlement permit: 30 days for projects with 25 units or fewer, and 45 days for 26 or more. The clock pauses if another public agency must review the application, and the city must notify you.

For homeowners: a well-prepared, complete plan set matters more than ever, because you get two review rounds, not unlimited ones. For contractors: shorter, more predictable timelines mean less carrying cost between design and groundbreaking.

Know Infrastructure Costs Early: SB 1014

SB 1014 lets applicants request an early estimate of the on-site and off-site improvements a city or county may require, such as sidewalks and sewer work. Reporting on the law says cities must disclose these requirements within 30 days of receiving a housing application. After that, a city generally cannot require improvements that were not on the initial list unless it makes specific health and safety findings or the project changes. The estimates are not legally binding.

Townhomes and Small Lots: AB 1751 and SB 1116

AB 1751, the Missing Middle Townhome Ownership Act, creates a ministerial, CEQA-exempt path for qualifying townhome projects of up to 150 units. Projects must be three-story townhomes averaging no more than 1,750 net habitable square feet, and projects of 11 or more units must include affordable units. Environmentally sensitive and historic sites are excluded.

SB 1116 expands the Starter Home Revitalization Act. It removes the 5-acre cap on multifamily-zoned lots, allows parcel size averaging, caps front setbacks at 10 feet and sets a 60-day deadline for acting on final maps. It also voids certain CC&Rs that would block these projects, except those from common-interest developments under the Davis-Stirling Act.

Related changes extend approved tentative maps from 24 to 48 months (SB 1169) and limit appeals of subdivision maps for qualifying infill projects (SB 677). If you own an older lot in Los Angeles, the San Fernando Valley or the surrounding area, it is worth asking whether a multi-unit project now pencils out. See our guide to SB 9 lot splits for another path.

ADUs: Fees and Detached Units

Reports on the package say SB 1117 changes the impact fees local governments can charge on ADUs larger than 750 square feet, and AB 956 allows up to two detached ADUs on a qualifying single-family lot. If you are weighing a backyard unit, use our ADU calculator to estimate cost and rental return, and read about our ADU services. Exact fee amounts and eligibility depend on your city, so verify them before you budget.

Factory-Built Housing and Window Replacement

Several bills (including AB 1815, AB 2058 and AB 2185, as reported) aim to streamline inspection of factory-built housing and align affordable-housing financing with how modular builders are paid. Press coverage also reports that AB 908 simplifies approval of energy-efficient window replacements and limits some homeowners association barriers. We have not confirmed the final text of every bill, so treat these summaries as a starting point and confirm details before relying on them.

What Homeowners Should Do Now

• Check your lot's zoning and ADU or townhome eligibility with a licensed contractor before drawing plans.
• Submit complete plans the first time, since two review rounds is the new ceiling.
• Ask your contractor for an early infrastructure and fee estimate.
• Do not assume a permit is no longer needed. These laws speed up review. They do not remove building code or safety requirements.

What Contractors Should Do Now

• Track the January 1, 2027 effective date and how each city implements the changes.
• Tighten your plan submittals to pass within two plan check rounds.
• Price projects with early infrastructure estimates to avoid surprise costs.
• Evaluate townhome, small-lot and factory-built options for new revenue.

Will This Fix the Housing Crisis?

Probably not alone. Land, labor, insurance, financing and material costs still drive prices, and local implementation will decide how much time these laws actually save. The governor's office reports annual housing units built rose from about 70,000 in 2018 to about 111,000 in 2024. Still, faster permits are a real win for anyone building or remodeling.

Plan Your Project With 1 Smart Build

1 Smart Build is a licensed Los Angeles residential contractor handling design, permits and construction. Call us or request a free consultation, and we will tell you which of these changes apply to your property. This article is general information, not legal advice.

Frequently Asked Questions

When do the new California housing laws take effect?

Most of the bills signed on September 29, 2026 take effect January 1, 2027.

Do I still need a building permit?

Yes. The laws speed up and limit review, but they do not remove permit or safety requirements.

How many plan checks can a city require now?

No more than two plan check and specification review rounds per building permit application under AB 1621.

Can I build two ADUs on my lot?

Reports say AB 956 allows up to two detached ADUs on qualifying single-family lots. Eligibility depends on your lot and city, so confirm before designing.