San Diego ADUs in 2025: What Home Owners Owners Should Know

As of August 4, 2025, San Diego’s ADU landscape is shifting. Major policy changes and community concern have reshaped accessory dwelling unit development. This update explains what’s new, what the debates are, and how thoughtful design can keep your ADU both compliant and high‑performing.

ADU Rollback: What Just Changed

On June 16, 2025, the San Diego City Council approved 25 reforms to the city’s ADU and JADU regulations. The key change: limiting how many ADUs can be built on single‑family lots. Now, a property up to 8,000 ft² can support four ADUs, up to 10,000 ft² can have five, and properties larger than that are capped at six. Inside San Diego reports the revisions applied following years of community pushback.

In March, staff were directed to revisit the ADU bonus program, allowing multiple units on larger lots. The Council is now removing bonus eligibility in low-density zoning areas. Axios described the vote as the end of a YIMBY‑dominated policy era.

NIMBY vs. YIMBY in San Diego

The original ADU bonus program exceeded state requirements, helping ADUs make up nearly 20% of new housing permits in 2023. Axios notes the dramatic increase from just four ADU permits in 2015 to almost 2,000 in 2023.

Supporters say more ADUs help address affordability and density goals. Opponents cite traffic, parking, and neighborhood character concerns, a classic NIMBY reaction. Even San Diego’s planning commission endorsed height limits and caps, highlighting community character preservation. OB Rag covered the sentiment.

Policy Evolution: What’s Ahead

• Allowing ADU Sales: San Diego may soon let homeowners sell ADUs as independent units via a condominium map, in line with California’s AB 1033. Approval by July 2025 remains pending. Better Place Design outlines the timeline.

• Fee Reforms: New infrastructure fees apply, but deed-restricted affordable ADUs may be exempt in higher-opportunity areas. City of San Diego documents the proposed fees.

• Fire Safety and Height Limits: Two-story height caps and setbacks are now enforced, especially in fire hazard zones and cul-de-sac properties. KPBS details the changes.

Where Upwell Steps In

Upwell Builders specializes in designing ADUs that meet new regulations, ease neighbor concerns, and deliver real revenue. Here’s how we help:

• Code-Aligned Architecture: We design to current height limits, setbacks, and unit caps.

• Designs That Blend In: We select finishes and scale ADUs to match neighborhood character while respecting zoning rules.

• Potential ADU Sales Strategy: When the ordinance passes allowing ADU condominium mapping, we’ll plan units to be legally separable.

• Fee-Smart Planning: We structure projects to navigate new infrastructure fee rules and explore exemptions for affordable units.

Planning Tips for STR Operators

Whether you plan to rent or eventually sell, preparation is key:

• Check current lot-size-based unit caps.

• Design to meet two-story limits and fire setbacks.

• Plan for durability and guest comfort in finishes and flow.

• Consider future resale strategies if separate ADU sales become allowed.

What It Means for San Diego Housing

San Diego’s approach reflects a balancing act: supporting density and affordability while respecting local voices. The rollback highlights the tension between housing goals and community resistance. Still, ADUs remain among the most scalable strategies to add small homes—and thoughtful design can play a role in easing conflict.

Final Thought

ADU policy in San Diego is evolving rapidly. Some options are tightening. New ones are emerging. That makes planning well, building right, and designing thoughtfully more important than ever. At Upwell, we stay ahead of rules so your ADU not only meets requirements but performs; whether as STR income, rental stability, or a sellable asset.

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