#1 ADU Contractor in Agoura Hills
Custom Builds by Horizon Remodeling

Finding the right adu contractor in Agoura Hills means understanding both state law and the specific local conditions that shape what you can actually build on your parcel. California consolidated its ADU statutes into Government Code sections 66310 through 66342 in 2024, and those rules were updated again on January 1, 2026. Under the current framework, square footage is counted as interior livable space, and your application goes to the City of Agoura Hills Building and Safety Division, which has 15 business days to determine whether your submission is complete and 60 days to approve or deny it. Approval is ministerial, meaning no public hearing and no discretionary design review.

State law sets a floor of protections that apply regardless of which city your parcel sits in. A local agency cannot limit an ADU to less than 850 square feet of interior livable space, or less than 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 units of 750 square feet or less are not subject to impact fees.

Los Angeles County has 88 incorporated cities, and the permit counter changes from one to the next even where the state rules stay constant. That distinction matters. The county’s own ADU ordinance, amended in July 2025 and covering only unincorporated territory, was found non-compliant with state law by the California Department of Housing and Community Development in December 2025. Among other findings, it caps detached ADUs on a multifamily lot at two where state law allows up to eight. Agoura Hills is an incorporated city, so its permits run through its own Building and Safety Division, but the county example is a useful reminder that local handouts are not always current with the statute.

The physical character of Agoura Hills adds another layer of planning. Most of the housing stock was built in the 1970s and 1980s, after the Ventura Freeway opened and tracts were subdivided across hillside and canyon terrain before the city incorporated in 1982. Areas like Old Agoura, Morrison Ranch, Lake Lindero, and Liberty Canyon reflect that era and that topography. Many lots sit on sloped or graded pads rather than flat ground, which directly affects where a detached unit can be placed, how far utility lines need to run, and whether a garage conversion or a new detached structure is the more practical path.

One local factor carries weight throughout the entire city: Agoura Hills sits within a CAL FIRE designated Very High Fire Hazard Severity Zone, which means wildland-urban interface construction standards apply to exterior work on any new structure. Material choices for siding, roofing, venting, and glazing are subject to those requirements, and we account for them in design before anything goes to plan check. We walk every parcel to evaluate setbacks, grade, equipment access, and utility routes before drawing a single line, because the lot decides most of what is possible well before the Building and Safety Division sees the application.