ADU Construction — Detached, Attached, Garage Conversion & Junior ADUs

Planning & Permits

Every ADU project starts with a site visit. We review your lot, discuss what you want to build, and look at what's realistic for your property — setbacks, existing utilities, access, and any site conditions that affect the design. This first conversation is where most of the planning questions get answered, and it's where we agree on the scope of the project before any plans are drawn.

Once the direction is set, we prepare architectural plans and engineering, then move into the permit process for your project's jurisdiction. For properties within the City of Los Angeles, we submit plans to LADBS, coordinate with inspectors through plan check, and carry the project all the way through final sign-off. Several cities and unincorporated areas we serve — including Glendale, Pasadena, Calabasas, Beverly Hills, West Hollywood, and unincorporated Los Angeles County — have their own building department instead of LADBS, and we manage that jurisdiction's process the same way. Permits are one of the most confusing parts of building an ADU for first-time clients — our team handles the full permit process so homeowners never have to navigate the permitting system on their own.

Construction Process

After permits are approved, we move into the build. Hillstar Construction Inc holds the prime contract and manages the entire build: our crew handles foundation work, framing, drywall, and finish work directly, and we subcontract electrical, plumbing, and HVAC to appropriately licensed specialty contractors we oversee on your behalf. The same team you meet on day one stays on the project through final inspection, which keeps quality and scheduling consistent from start to finish.

The construction phase follows a standard sequence: foundation and rough framing first, then mechanical rough-ins, inspections, insulation and drywall, interior finishes, and final inspections with the jurisdiction's building department. We give homeowners regular updates throughout so nothing is a surprise, and we stay on the same jobsite until the work is done. Our full-service approach covers more than just ADUs — we also handle kitchen and bath work, additions, and complete home remodeling projects across LA.

Frequently Asked Questions

How long does an ADU project take in Los Angeles?

Timelines vary by project and by how quickly permits move through your project's city or county building department. Most ADU builds we work on complete in about 3 to 6 months once construction begins. We provide a clear schedule at the consultation so you know what to expect at each phase.

Do you handle permits and inspections?

Yes. For properties in the City of Los Angeles, we handle the full LADBS permit process from plan submission through final inspection, coordinating directly with city inspectors at every stage. For properties in other jurisdictions we serve — including Glendale, Pasadena, Calabasas, Beverly Hills, West Hollywood, and unincorporated Los Angeles County — permits go through that city's or county's own building department instead, and we manage that process the same way. Homeowners don't have to deal with the paperwork or back-and-forth themselves.

What types of ADUs can I build on my property?

That depends on your lot size, setbacks, and existing structures. Detached, attached, garage conversion, and above-garage ADUs are all common options in LA, and we'll walk through which ones are realistic for your specific property during the first site visit. Our cost and ROI guide for building an ADU in Los Angeles covers the financial side of each option.

What neighborhoods do you serve?

We work with homeowners across the greater Los Angeles area, with a focus on the San Fernando Valley and the Westside. That includes Woodland Hills ADUs, Encino ADUs, Sherman Oaks, Tarzana, Studio City, Beverly Hills, Bel Air, and West Hollywood, among others. If you're nearby and not sure whether we cover your area, give us a call.