California Just Passed Four New ADU Laws | Anthony Young - Appraiser

by Patti Gregory

Very important information about ADU's

Governor Newsom just signed several new housing bills that directly impact Accessory Dwelling Units (ADUs) and Junior ADUs (JADUs) — and they could change how you price, list, and advise your clients starting now.

Let’s break it down.

The Four Bills

AB 462 – Coastal & Emergency Zones
ADUs in certain coastal or emergency-declared counties are now exempt from the Coastal Development Permit process.
Faster approvals
Lower risk for owners in affected zones

AB 1154 – Parking & JADU Updates
Local agencies can’t require parking for ADUs under 500 sq ft.
It also updates JADU rules:

Owner-occupancy may depend on shared vs. separate sanitation
Rentals must be 30 days+, preventing short-term Airbnb conversions

SB 9 – The Big One (Recap)
This earlier law still packs a punch: it allows two primary units per single-family lot and streamlines lot splits.
It’s the backbone of California’s infill housing movement.

SB 543 – Fee & Definition Refinements
Clarifies what counts as “interior livable space” for JADUs and tightens rules on impact fee exemptions for smaller units (≤ 750 sq ft).
Local agencies must keep their ADU/JADU ordinances compliant with state law.

What This Means for You

For Sellers:
Listings with ADUs or ADU potential just became more valuable in certain markets. Especially if your property falls in an affected zone — reduced red tape means faster permit turnaround and stronger buyer appeal.

For Buyers & Investors:
Ask smart questions:

Does the property qualify under AB 462?
Is the ADU small enough (≤ 500 sq ft) for AB 1154’s parking relief?
Are there still local restrictions under SB 543 that might limit rentability?

For Appraisers & Agents:
You’ll need to start documenting:

ADU size, permit history, and local compliance
Market reaction to these rule changes
New cost savings from parking/fee exemptions
And when in doubt, note it in your addendum — it matters for credibility.

Why It Matters

California’s message is clear:

“We’re done making it hard to add housing.”

These bills keep tightening the screws on local resistance and pushing ADU development statewide.
The result? More units, new valuation challenges, and an evolving conversation about what “highest and best use” really means in residential neighborhoods.

Quick Takeaways

Fewer permits required for ADUs in coastal/emergency zones
No parking requirements for units under 500 sq ft
Fee exemptions and faster approvals for small ADUs
More flexibility under SB 9 for lot splits and duplex conversions

Courtesy of Anthony Young

Certified Appraiser | valueduadit.com