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If you are planning to add living space to your property, working with an experienced adu contractor in Pomona means understanding both the state rules that set the floor and the local process that handles your application. California reorganized its ADU statute into Government Code sections 66310 through 66342 in 2024, and further changes took effect January 1, 2026. Square footage is now defined as interior livable space, and once you submit, the reviewing agency has 15 business days to confirm your application is complete and 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review stands between a complete application and a decision.

In Pomona, that application goes to the City of Pomona Building Safety Division, part of the Development Services Department. No unusual local overlay applies here, so what governs your project is the building code itself and the age of your specific house. That is a straightforward starting point compared to some jurisdictions, but it still means the permit counter, the plan check staff, and the inspection sequence are specific to Pomona rather than shared with neighboring cities. Los Angeles County has 88 incorporated cities, and the agency you deal with changes from one to the next even when the underlying state law does not. As a reminder of why that matters, the county’s own ADU ordinance covering unincorporated territory was found non-compliant with state law by the California Department of Housing and Community Development in December 2025, partly because it capped detached ADUs on multifamily lots at two where state law allows up to eight. That ordinance does not govern Pomona, but it illustrates why a local handout is not always current with the statute.

Pomona’s housing stock reflects a long and uneven development timeline. Older wood-framed homes near downtown, some dating to the city’s late nineteenth century roots, sit on different lots with different constraints than the larger two-story tract homes built in Phillips Ranch and other hillside subdivisions south of downtown since the 1980s. That variation shapes nearly every decision on an ADU: where a detached unit can physically sit, how far utility lines have to run, and whether converting an existing garage or building a new structure is the more practical path for your parcel.

Before we draw anything, we walk the property and assess setbacks, grade, equipment clearances, and utility routing. The gap between a detached new build and a garage conversion often comes down to what we find during that site review rather than what looks obvious on a map. For properties with mature lots near the Downtown Arts District or along older residential streets, utility distances and foundation conditions tend to drive the conversation. On the hillside tracts, grade and access for construction equipment are often the first questions we have to answer.

State law sets protections that apply regardless of where your parcel sits. A local agency cannot hold an ADU below 850 square feet of interior livable space, or below 1,000 square feet if the unit has more than one bedroom. Side and rear setbacks cannot exceed four feet. Owner-occupancy cannot be required as a condition of building an ADU. Adding a unit cannot trigger a fire sprinkler retrofit of the main house. And there are no impact fees on a unit of 750 square feet or less. We coordinate the full scope of work through the Pomona Building Safety Division and manage the trades required to complete your project. Contact us to request a free estimate and talk through what your lot and your goals actually support.