California has spent years making accessory dwelling units easier to approve. Fresno is now confronting the harder question: whether ordinary homeowners can actually afford to build them.
Accessory dwelling units, or ADUs, are small independent homes built on the same property as a primary residence. They can provide rental housing, space for relatives, a place for an aging parent or a way for a homeowner to earn additional income. They can also remain an attractive idea that never gets past the permit stage.
The state’s numbers show why ADUs have become central to California’s housing strategy. The California Department of Housing and Community Development’s updated ADU handbook reports that annual ADU permits rose from 1,336 in 2016 to 30,354 in 2024. ADUs represented more than 26 percent of all homes permitted statewide in 2024.
That is a significant change in what California allows and counts as housing production. It is not, by itself, proof that enough homes were completed, that they are affordable or that they reached people facing the greatest housing pressure.
Fresno has removed some of the design burden
Fresno’s response has included pre-approved designs intended to make the process less intimidating and less expensive. The city’s ADU program offers five pre-approved plans, ranging from a 340-square-foot studio to a 1,015-square-foot three-bedroom home. The plans include solar provisions and can be used for different neighborhood settings.
Fresno County also offers pre-approved plans for eligible homeowners in unincorporated areas. Those programs address a real obstacle: homeowners should not have to begin every project by paying for a wholly new design.
But a pre-approved plan is not a construction contract. It does not eliminate site work, utility connections, sewer or septic questions, fire requirements, financing costs, labor, materials, inspections or delays. Fresno’s own program notes that fire-sprinkler and fire-access requirements can depend on the existing residence, the location of the ADU and available fire-water infrastructure.
In other words, the plan may be ready before the property is.
The gap between permission and production
That gap is becoming clearer as ADUs spread nationally. A recent Pew analysis found that cities with permissive ADU rules issued far more ADU permits than cities with restrictive rules. But the same analysis also emphasizes that legalizing ADUs is not the same as building them. Financing, parking rules, owner-occupancy requirements, discretionary review and construction costs can still determine whether a project moves forward.
Pew estimates that cities and towns issued 61,655 ADU permits nationally in 2025, up from 4,962 in 2016. The growth supports the case for legal reform. It also makes the next measurement problem more important: how many permitted units become completed homes?
Fresno needs to answer that question locally. The useful numbers are not only applications and approvals, but completed inspections, certificates of occupancy, project timelines and abandoned permits. Without those measures, public officials can describe an active housing program without knowing how much housing it actually produced.
The same distinction applies to affordability. An ADU can add to the housing supply while remaining too expensive for the households most affected by Fresno’s shortage. A homeowner who finances construction through existing equity is in a different position from a homeowner with limited savings, a high mortgage balance or no access to conventional credit.
Construction cost is only one part of the calculation. The owner must also consider whether the finished unit will generate enough rent to cover debt, maintenance, insurance and property taxes. If the resulting rent is close to the cost of an ordinary apartment, the ADU may still provide useful housing, but its contribution to affordability is narrower than the permit count suggests.
Who benefits from the backyard strategy?
ADUs can serve several different purposes, and those purposes should not be treated as interchangeable. A unit occupied by a grandparent may support aging in place. A unit rented to an adult child may help a family remain together. A unit rented at market price may add supply without being affordable to a low-income tenant. A unit used for short-term lodging may provide income but not long-term housing.
Those differences matter because California’s policy language often treats the ADU as a flexible solution. Flexibility is useful, but it can also make success difficult to define. A program designed to support multigenerational households may need different assistance from one designed to expand rental housing. A rural property may face septic, road and emergency-access problems that do not appear in a city-lot application.
Fresno’s agricultural region adds another practical question. Are ADUs reaching farmworker households and communities outside the urban core, or are they concentrated among homeowners with the land, financing and administrative time to manage a complex construction project?
The infrastructure question is smaller in scale, not absent
ADUs are often described as low-impact infill because they use land that already contains a home. That can be true. It does not mean they have no public or infrastructure consequences.
Some properties may require electrical upgrades, water or sewer work, drainage improvements, fire sprinklers or changes to emergency access. In unincorporated areas, septic capacity and road conditions can be decisive. The important question is not whether every ADU requires a major public project. It is whether Fresno and Fresno County know which requirements are preventing construction and who pays when improvements extend beyond the property itself.
That information would help separate genuine barriers from paperwork problems. It would also show whether pre-approved plans are reducing total project costs or mainly reducing architectural costs while leaving the largest expenses untouched.
Fresno is testing the next phase of ADU policy
California has largely answered the legal question: Can homeowners be allowed to build secondary homes? The state’s permit numbers show that changing the rules can produce a large increase in proposed housing.
Fresno is helping test the question that follows: Can those homes be built by people without substantial wealth, and can they become housing for people who cannot afford the market as it currently exists?
The answer will require more than another announcement about permissive zoning. It will require public data showing the number of applications, permits, completed units and abandoned projects. It will require actual construction budgets, financing terms and rental prices. It will require officials to identify whether the program serves renters, relatives, caregivers, older adults and farmworker households—or primarily homeowners who already have the strongest financial position.
ADUs are neither a housing miracle nor a failed policy. They are a tool whose value depends on what happens after permission is granted.
For Fresno, the next important number is not how many backyard homes the law allows. It is how many people can actually build, occupy and afford them.
