California’s New ADU Laws for 2025: What You Need to Know

As California continues to tackle its ongoing housing crisis, new legislation for Accessory Dwelling Units (ADUs) in 2025 is set to revolutionize how homeowners and property developers can create additional living spaces. These updated laws aim to simplify the permitting process, expand opportunities for building ADUs, and ultimately provide more affordable housing options across the state.

Key Changes to ADU Laws in California for 2025

Let’s dive into the most significant updates for ADU regulations taking effect in 2025:

1. SB 1211: Expanded ADU Limits for Multifamily Properties

Starting January 1, 2025, multifamily properties can now include up to eight detached ADUs, compared to the previous cap of two. However, the number of ADUs cannot exceed the total number of existing units on the property. This change provides greater flexibility for property owners to maximize their rental potential while addressing housing demand.

2. AB 2533: Legalizing Unpermitted ADUs and JADUs

AB 2533 introduces a pathway for unpermitted ADUs and Junior ADUs (JADUs) built before January 1, 2020, to become compliant. Local agencies are no longer allowed to deny permits for these units based on building standard violations unless the structure is deemed substandard. This law helps homeowners bring their ADUs into legal standing without costly rebuilds or removals.

3. AB 434: Pre-Approved ADU Designs

By January 1, 2025, all cities and municipalities in California must adopt pre-approved ADU designs. This initiative streamlines the approval process by providing homeowners with ready-to-use, compliant plans, reducing delays and simplifying construction. Homeowners can now save time and money while meeting state standards for ADUs.

4. AB 976: Permanent Removal of Owner-Occupancy Requirements

Under AB 976, owner-occupancy requirements for ADUs are permanently removed. Homeowners can rent out their ADUs without needing to reside on the property themselves. This flexibility is a game-changer for those looking to maximize rental income or convert their properties into income-generating assets.

Why These Changes Matter

The new ADU laws for 2025 provide opportunities for homeowners and developers to create more housing while reducing regulatory hurdles. Here are some of the benefits:

• Increased Housing Supply: By allowing more detached ADUs and legalizing previously unpermitted units, California is expanding its housing inventory.

• Streamlined Processes: Pre-approved designs eliminate bureaucratic delays, making it easier to build compliant ADUs quickly.

• Flexibility for Property Owners: The removal of owner-occupancy requirements and expanded ADU limits on multifamily properties allow for greater financial opportunities.

How to Take Advantage of the New ADU Laws

If you’re considering building an ADU in 2025, here are a few tips to get started:

• Consult Local Regulations: While the new laws set statewide standards, local municipalities may have additional requirements.

• Leverage Pre-Approved Plans: Check your city’s list of pre-approved designs to save time on permitting. Additionally, we can help you tweak these pre-approved plans to better suit your specific needs, providing a middle ground between a completely new project and a generic design.

• Work with Professionals: Partner with Bonne Designs, experts in ADU construction and compliance, to ensure your project is handled seamlessly and professionally.

• Plan for Rental Income: With no owner-occupancy requirements, ADUs are now an even more attractive option for generating passive income. While we do not provide consulting services on this matter, we can refer you to trusted professionals who specialize in ADU planning, permitting, and construction.

Final Thoughts

California’s 2025 ADU laws mark a significant step forward in addressing the state’s housing challenges. By simplifying the approval process, expanding building opportunities, and offering greater flexibility, these changes make it easier than ever to create additional housing. Whether you’re a homeowner looking to add an ADU or a property developer planning multifamily investments, 2025 is the year to explore the potential of ADUs.

Ready to start your ADU project? Contact us today for expert guidance and resources to bring your vision to life.

• What is an ADU?

  An Accessory Dwelling Unit (ADU) is a secondary housing unit on a single-family or multi-family property. Often referred to as granny flats, in-law units, or backyard cottages, ADUs can be detached, attached, or converted from existing spaces like garages.oes here

• What are the size limits for ADUs in 2025?

  The 2025 laws allow:

  • Detached ADUs: Up to 1,200 square feet.

  • Attached ADUs: Limited to 50% of the primary residence’s size, or 850 square feet for a one-bedroom unit and 1,000 square feet for a two-bedroom unit.

  Local jurisdictions may impose additional restrictions.

• How many units can I add to my property under the new laws?

  In most cases:

  • Single-family properties can add one ADU and one Junior ADU (JADU).

  • Multi-family properties may add up to two detached ADUs and convert unused spaces (e.g., garages or storage areas) into additional units, subject to local limits.

• What are the parking requirements for ADUs?

  Parking is generally waived for ADUs located near public transit or when converting existing structures. Detached ADUs usually require one parking space unless specific exemptions apply.

• How has the permitting process changed?

  The 2025 laws require local jurisdictions to approve or deny ADU applications within 60 days (reduced from 120 days). This faster timeline encourages quicker development.

• Can ADUs be rented out?

  Yes, ADUs can be rented, but they must comply with local ordinances. Short-term rentals (under 30 days) are generally restricted in most California cities.