San Diego’s ADU program so successful
it’s drawing a backlash
by Sal Rodriguez | June 6, 2025
Over the past decade, California lawmakers have enacted several laws legalizing and facilitating the development of accessory dwelling units. Also known as granny flats or casitas, ADUs are typically small units built on properties with an existing single-family home. Given their generally lower construction costs and the relative speed with which they can be built, ADUs have been seen as one way of quickly delivering much-needed housing.
The city of San Diego has been a standout in the production of these units. After a 2019 state law required cities to develop plans promoting the production of ADUs for moderate- and lower-income people, San Diego established what’s called the ADU Bonus Program to do just that.
As the city’s planning department explains in a fact sheet about the program, “The Affordable ADU Bonus program allows for the construction of one unrestricted ADU for every affordable ADU deed-restricted for 15 years. Outside of Transit Priority Areas (TPAs), projects would be limited to one additional unrestricted ADU. Within TPAs, the number of additional ADUs does not have a specific limit.”
These fairly lax provisions helped spur significant construction of ADUs across the city, both affordable and market-rate.
According to the Terner Center for Housing Innovation in early 2023, “Prior to the creation of the ADU Bonus Program, affordable ADUs were rare in San Diego. Within the first two years of implementation of the ADU Bonus Program, 295 deed-restricted ADUs to low or moderate-income households were in the process of being built.”
In addition, hundreds of market-rate units came up in that time as well. Reported the Terner Center, “In addition to the 295 deed-restricted ADUs, the program created 253 bonus ADUs over the 147 ADUs already allowed by state law. While these units are not deed-restricted, research from the Center for Community Innovation has found that on average, ADU rents are more affordable than other forms of new housing.”
This boom in ADUs has only continued, delivering much needed housing in a city where demand significantly outpaces supply.
A report from Chapman University last year deemed the city of San Diego’s housing market “impossibly unaffordable,” while a report from the state released in May indicated that a single person in San Diego County making about $93,000 would be considered low-income. ADUs alone won’t solve this problem, but they are a useful addition to the housing mix given the circumstances.
However, the ADU program has increasingly come under attack by people who don’t appreciate the idea of letting property owners build more housing on their property. In March, the San Diego City Council rebuffed a push by some to abolish the program but did agree to instruct city staff to scale back where the Bonus ADU Program can work.
As reported by the local PBS affiliate, “Mayor Todd Gloria is proposing a host of changes. He wants to roll back the ADU bonus program with new fees, parking requirements and restrictions in wildfire hazard zones. He also proposes totally eliminating the ADU bonus program in neighborhoods zoned for very low density.”
Among the changes approved so far by the council’s housing committee includes mandated distances from property lines and limits on the number of floors ADUs can be. Practically, these changes will just translate to fewer homes being available to people who want and need them.
Reading between the lines, and as confirmed by KPBS, this practically means cutting off housing opportunities in many of the city’s best off neighborhoods, which are also “associated with positive economic, educational and health outcomes for low-income families.”
Practical tweaks to the program addressing real problems are one thing, but housing regulations designed to spare grumpy constituencies from the horror of new housing should not be accepted.
The city of San Diego would be making a mistake in significantly cutting back on the Bonus ADU Program. But if it’s going to move ahead in doing so, as it appears it will, it should move to reduce barriers to housing throughout the city in other ways. After all, there’s a reason so much housing is being built through the program: there’s a lot of demand for it.
As usual, the key is for the government to get out of the way.
Manny Rodriguez and Saad Asad from YIMBY Democrats of San Diego County point out that, “Large parts of the city require every house to sit on at least 5,000 square feet of land. That blocks the kinds of starter homes and townhouses that once served working families.”
Then there are effective bans on apartments due to height limits in large areas of the city. And then there are hurdles property owners must jump through if a structure on their parcel happens to have been around for 45 years or older.
Regulations big and small add up. The city’s Bonus ADU Program has been a welcome case of a city setting fairly simple rules and getting out of the way. Now that the program is showing success, politicians feel the need to get in the way again. This seems to be a recurring pattern with successful housing policies. It’s as though politicians forget and don’t completely understand the benefits of housing and become startled as soon as something works.
Sal Rodriguez is opinion editor for the Southern California News Group and a senior fellow with the Pacific Research Institute. He is the author of Dynamism or Decay? Getting City Hall Out of the Way, published by the Pacific Research Institute.
