San Diego’s Latest Move on Housing Density
On Tuesday the City Council passed a closely watched measure that caps the number of Accessory Dwelling Units (ADUs) allowed on single-family lots. The San Diego housing ordinance 2025 was approved by a 5-4 vote and now heads to Mayor Todd Gloria for his signature. If signed as expected, the rules will take effect 30 days later—reshaping the way homeowners, investors and builders approach Accessory Dwelling Units in San Diego.
Why the City Council Set a Cap
In recent years, incentives at the state and local level removed many barriers to ADU construction. While that helped boost housing supply, some neighborhoods saw block-by-block transformations as multiple small units sprang up behind existing houses. At public hearings, residents cited:
- Parking shortages and traffic on streets designed for far fewer households
- Strain on aging sewer, water and electrical infrastructure
- Loss of mature trees and yard space that once separated homes
- Concerns about emergency vehicle access—especially in the city’s fire-prone canyons
Balancing those concerns with San Diego’s housing shortage led to the new limits, widely referred to as the San Diego ADU cap.
Exact Numbers: How many ADUs can I build in San Diego now?
The ordinance ties the ADU allowance directly to lot size:
- Lots < 8,000 sq ft — Maximum 4 ADUs
- Lots 8,001 – 10,000 sq ft — Maximum 5 ADUs
- Lots > 10,001 sq ft — Maximum 6 ADUs
Before this vote, some developers combined state “bonus” ADUs with junior ADUs to place eight, ten, or even more units on a standard parcel. The new San Diego ADU regulations end that practice on single-family lots while still allowing meaningful densification.
Wildfire Safety and Cul-de-Sacs
A second provision responds to San Diego Fire-Rescue Department feedback. ADUs may no longer be built on cul-de-sacs located inside high-wildfire-risk zones. Narrow roads and limited exit routes in those areas already make evacuation challenging; extra homes could put lives at risk. The cap reinforces broader city goals of climate resilience and public safety.
What This Means for Homeowners and Investors
While some see the cap as a setback, many property owners will find the ordinance still offers strong returns:
- 4–6 additional rental units on a single parcel can dramatically lower mortgage costs or create multigenerational living options.
- Knowing the maximum upfront helps avoid costly design revisions later in the permitting process.
- Neighborhoods may face less pushback, smoothing the public-notice phase for compliant projects.
Investors, however, should revisit their spreadsheets. Under previous assumptions of eight or more units, projected cap rates may no longer pencil out. Aligning pro-formas with the new limits will be essential before closing on land deals.
Practical Steps if You’re Planning an ADU in 2025
1. Verify your lot size. Pull the assessor’s parcel map or a recent survey so you know which tier—4, 5 or 6 units—you qualify for.
2. Check wildfire maps. Use the City’s Fire-Rescue hazard tool to confirm whether the cul-de-sac restriction applies.
3. Hire an architect familiar with San Diego ADU regulations. Firms that specialize in ADUs can optimize setbacks, height limits and parking waivers.
4. Submit plans quickly. Projects deemed complete before the effective date may be processed under old rules—time is money.
5. Engage neighbors early. Transparent communication about design, parking and landscaping can head off objections that delay approvals.
Voices from the Community
Encanto resident Lisa Becerra celebrated the vote after four and a half years
of advocacy. Geoff Hueter, chair of Neighbors for a Better San Diego, called the compromise a much better place than we were
while noting further tweaks may come. Those comments suggest the ordinance is not the final word—future councils could raise or lower the cap as housing trends evolve.
Stay Informed
City Hall will release formal guidelines once Mayor Gloria signs the bill. Track updates through the CBS 8 coverage or the City’s Development Services Department.
Bottom line: The San Diego ADU cap sets clear, lot-size-based limits while still encouraging gentle density. Whether you’re a homeowner adding a backyard flat for family or an investor eyeing cash-flow potential, understanding the new rules will be crucial to a successful project in 2025 and beyond.
Source: CBS 8 News