California continues to double down on housing expansion and this year brings another round of meaningful updates to ADU and JADU regulations. With Governor Newsom signing four new bills into law, the path to building accessory units just became faster, clearer, and in many cases, more profitable.

For agents, appraisers, homeowners, and investors across California, these changes will influence how you price, market, and evaluate properties starting now.

Here’s a breakdown of what matters most:

The Four New ADU Bills, Simplified

AB 462 – Coastal & Emergency Zones

For years, ADU construction in coastal areas has been slowed by additional permitting layers. AB 462 removes a major barrier by exempting ADUs in certain coastal or emergency-declared areas from the Coastal Development Permit process.

Why it matters:

• Faster approvals

• Less risk for homeowners in impacted zones

• Stronger buyer appeal for properties with ADU potential

AB 1154 – Parking Relief & JADU Updates

This bill focuses on smaller units and Junior ADUs (JADUs):

• Cities cannot require parking for ADUs under 500 sq ft

• Introduces updated JADU rules, including:

  • Owner-occupancy may depend on whether the unit has shared or separate sanitation

  • JADUs must be rented for 30 days or longer, curbing short-term rental use

Why it matters:

Small ADUs just got easier and cheaper to build and more attractive for long-term rental strategies.

SB 9 – Still Transforming Single-Family Neighborhoods

Although not new, SB 9 remains the backbone of California’s housing reform. It still allows:

• Up to two primary units on a single-family parcel

• Streamlined urban lot splits

Why it matters:

This law continues to provide major infill opportunities in suburban markets where land is scarce.

SB 543 – Fees, Definitions & Local Compliance

SB 543 cleans up and clarifies several ADU/JADU rules:

• More exact definitions of what counts as interior livable space for JADUs

• Tightened rules around impact fee exemptions, especially for units 750 sq ft or smaller

• Requires local agencies to keep their ADU ordinances aligned with state law

Why it matters:

Clearer rules = fewer surprises for buyers, sellers, and builders. And smaller ADUs (<750 sq ft) continue to benefit from meaningful cost savings.

What These Changes Mean in Today’s Market

For Sellers

Properties with an existing ADU or clear ADU potential are becoming more valuable. In certain coastal and emergency-designated regions, the reduced red tape alone could strengthen buyer demand.

Consider highlighting:

• ADU size and layout

• Permit history

• Compliance with the updated laws

• Rental potential under the 30-day rule

For Buyers & Investors

Investors should now include a few new questions in their due diligence:

• Does the property fall within an AB 462-eligible zone?

• Is the ADU small enough to qualify for AB 1154’s parking exemption?

• Are there local fee or rentability considerations tied to SB 543?

These factors directly impact projected income and ROI.

Why This Matters

California’s message is unmistakable: housing creation must accelerate.

With every new bill, the state continues tightening restrictions on local resistance and clearing pathways for homeowners to add density.

The result?

• More units

• Changing valuation dynamics

• New opportunities for owners and investors

• And a steady shift in how “highest and best use” is interpreted in residential neighborhoods

ADUs aren’t side projects anymore, they’re becoming a cornerstone of California housing.

Key Takeaways

• Faster approvals for ADUs in certain coastal and emergency-declared counties

• No parking requirements for ADUs under 500 sq ft

• Fee exemptions and savings for smaller ADUs (≤ 750 sq ft)

• Ongoing flexibility for lot splits and duplex conversions under SB 9

Final Thought

ADU literacy isn’t optional anymore, it’s a competitive advantage. Understanding these new rules can help you guide owners toward smarter improvements and help buyers recognize hidden value.

If you’d like help evaluating ADU potential on your property, or want an expert look at your market’s latest ADU activity, our team at Craft & Bauer is here to help.