#1 ADU Contractor in San Gabriel
Custom Builds by Horizon Remodeling

Hiring an adu contractor in San Gabriel means working inside a permit system run by the City of San Gabriel, which issues building permits for all construction within city limits. California consolidated its ADU rules into Government Code sections 66310 through 66342 in 2024, and those rules were updated again on January 1, 2026. Under the current statute, square footage is calculated as interior livable space, and the city has 15 business days to determine whether a submitted application is complete, then 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review stands between a compliant application and a permit.

One thing worth understanding about the regional picture is that Los Angeles County contains 88 incorporated cities, and the permitting counter changes from one to the next even where state rules stay the same. The county maintains its own ADU ordinance covering unincorporated territory, and that ordinance was found non-compliant with state law by the California Department of Housing and Community Development in December 2025. Among the findings, it caps detached ADUs on a multifamily lot at two where state law allows up to eight. That ordinance does not govern San Gabriel, but it is a clear reminder that a local handout or a quick online search is not always a reliable substitute for reading the current statute.

San Gabriel itself has no unusual local overlay that complicates the review, so the governing factors are the building code and the age of the house on the parcel. That matters in a city whose residential fabric is mostly single-family houses and small multi-unit buildings on modest valley lots, much of it built during the middle and later twentieth century. Properties near Smith Park, the Vincent Lugo Park area, or along the Broadway blocks often carry older utility connections and foundation conditions that have to be evaluated before a unit layout can be drawn.

The lot decides most practical questions. We walk each parcel and check setbacks, grade, equipment access, and utility routes before a line goes on paper. A detached build makes sense on some properties; a garage conversion makes more sense on others. That site assessment is what keeps a project from running into problems at the plan-check stage rather than getting resolved early, when changes are straightforward.

State law sets a floor of protections that apply regardless of where the parcel sits. A local agency cannot cap an ADU below 850 square feet of interior livable space, or below 1,000 square feet for a unit with more than one bedroom. Side and rear setbacks cannot exceed four feet. Owner-occupancy cannot be required as a condition of building. Constructing an ADU 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 across trades, with specialty portions handled by appropriately licensed subcontractors, so the project moves through the City of San Gabriel permitting process as one organized effort.