New ADU amendments and what they could mean for San Diego

Accessory Dwelling Units (ADUs) have quickly become one of California’s most promising responses to the housing crisis. In San Diego, ADUs have gained particular momentum, offering flexible and more affordable ways to add much-needed housing within existing neighborhoods. In recent years, ADUs have accounted for nearly 20% of all new housing permits issued by the city.

While ADUs are still a common-sense solution to our critical housing needs, the city of San Diego is considering significant changes to its ADU policies. In response to community feedback and evolving urban needs, city officials are looking at amendments aimed to balance the city's housing goals with maintaining neighborhood character and safety concerns. These proposed amendments could reshape how and where ADUs are built and offer a glimpse into the evolving role ADUs are expected to play in the city’s future.

Understanding the Proposed Changes

San Diego’s current ADU regulations are among the most permissive in the state. The ADU Density Bonus Program, established in 2020, allows property owners to construct additional ADUs on their lots if they commit to making some units affordable for low- to moderate-income households. This program has been instrumental in increasing housing production, particularly in areas where development had historically been limited.

However, as ADU construction has surged, so have concerns about overbuilding, infrastructure strain, parking shortages, and changes to neighborhood character. In response, city officials are currently evaluating 24 proposed amendments to both the state ADU program and San Diego’s ADU Density Bonus Program. 

Key proposals include: 

• Adjusting ADU Distribution: Encouraging more units in areas already zoned for higher density, such as neighborhoods near public transit and commercial corridors, while limiting intensive ADU development in single-family residential zones.

• Community Infrastructure Fee: Introducing a fee for certain types of bonus ADUs to fund public improvements like upgraded sidewalks, lighting, and street trees in areas experiencing increased housing density.

• Enhanced Fire Safety Measures: Requiring additional fire safety measures, such as fire sprinklers and secondary egress routes, for ADUs built in high-risk wildfire zones.

• Revised Parking Requirements: Applying parking requirements to ADU developments in areas that aren’t transit-accessible, where residents are more likely to rely on cars.

Timeline of Key Events (all 2025):

• May 1: The San Diego Planning Commission reviewed and advanced the 24 proposed amendments to the ADU Home Density Bonus Program. 

• May 15: The City Council's Land Use & Housing Committee approved the proposed ADU reforms in a 3-1 vote. 

• June (Anticipated): The full City Council is expected to consider and vote on the proposed ADU amendments. If approved, these changes will formalize the scaling back of the Bonus ADU Program in specified zones and implement new regulations citywide.

• Late July/Early August (Expected): The Planning Department plans to present additional reforms to the City Council. These may include new requirements for parking and infrastructure fees associated with ADU developments.

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Why This Matters for San Diego

The proposed changes signify a shift in San Diego’s approach to ADUs. They aren’t intended to roll back progress but to refine existing policies, preserving the city’s commitment to housing innovation while addressing legitimate concerns from neighborhood groups and communities.

San Diego’s housing shortage remains acute, with rising rents and younger generations increasingly priced out of homeownership. In this context, ADUs offer a scalable and sustainable option: small homes that make use of existing land, require minimal new infrastructure, and can serve a wide range of housing needs.

But if ADUs are to become a long-term and meaningful part of the solution, their integration into the urban landscape must be thoughtful and responsive. That’s the balance San Diego is now trying to strike.

What This Means for Homeowners and Residents

If you’re a homeowner thinking about building an ADU, or if you simply live in a neighborhood where ADU construction is happening, these changes may affect what’s possible in your community.

The proposed amendments are designed to provide clearer guidance on where ADUs are best suited, how they should be integrated into existing neighborhoods, and how their impact on infrastructure and services can be mitigated. They also reflect a larger shift in how we think about housing. In an era defined by climate change, demographic shifts, and economic uncertainty, cities can no longer afford to expand outward. Instead, they must find ways to grow more intelligently within their existing boundaries. ADUs, when done well, are a prime example of how that can happen.

What’s Next?

The City of San Diego is currently seeking public input on the proposed changes, with the aim of finalizing a set of amendments later this year. This is an important moment for community members, housing advocates, and design professionals to help shape the future of the city’s housing strategy. If you care about affordable housing, urban design, or simply the changing shape of San Diego neighborhoods, this is an opportunity to engage in the conversation. The decisions made now could have long-lasting implications for housing access and neighborhood livability across the city.

ADUs have evolved from a niche concept to a mainstream housing solution, particularly in high-cost regions like Southern California. San Diego has been at the forefront of embracing ADUs, not merely as a temporary fix but as a central component of its urban development strategy. As the city fine-tunes its policies, it has the chance to set a national example: demonstrating how ADUs can be integrated into an urban environment thoughtfully, equitably, and at scale. These homes may be small, but they have the potential to make a significant impact on the future of housing.

If you’re considering building an ADU or interested in understanding the forces shaping San Diego’s housing future, this is the time to tune in. Change is coming—and it might just be in your backyard.

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Xavier Rodriguez is with ADU Geeks, San Diego’s leading ADU consulting and project management firm. In 2024, the company was ranked No. 1 on the San Diego Business Journal’s Fastest Growing Private Companies list in the Small Business category, achieving 594.3% revenue growth.

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 Sources:

City of San Diego Official Website: Regulatory Updates San Diego | San Diego Post: City Council Reconsiders Key ADU Incentive | SDNews.com: City Plans to Revise Accessory Dwelling Unit Bonus Program | University City News: Memo to City Council Members re ADU Home Density Bonus Program- University City Community Association | Times of San Diego: Mayor Todd Gloria Announces Proposed Reforms to ADU Program | GlobeSt.com: San Diego Rolls Back ADU Bonus from Zones with Large Lots | Axios San Diego: Council Begins Rolling Back ADU Policy | OB Rag: Neighborhood Activists Mobilizing Against Bonus ADU Program