- Typical cost
- $120,000 – $350,000 depending on size, type and site conditions
- Typical timeline
- Construction in as few as 120 working days once permits are issued; 8–14 months from first site visit to final inspection
- Permits through
- Pasadena Permit Center
- Service area
- Pasadena, San Gabriel Valley
What We Build
Detached new-build ADUs, attached ADUs off the main house, garage conversions, and JADUs. If you already have an unpermitted unit in the back, we can also walk you through legalizing it instead of tearing it out.
- Detached ADUs up to 1,200 sq ft
- Attached ADUs sharing a wall with the main home
- Garage and carport conversions
- Junior ADUs (JADUs) inside the existing footprint
- Legalizing existing unpermitted units
ADU & Garage Conversion Conditions in Pasadena
Behind the plaster, these houses need the same things: new supply and drain lines, a full rewire, foundation bolting and real insulation. The craft is making new work read as original, which means matching trim profiles, window proportions and rooflines rather than substituting stock parts. Permits go through the Pasadena Permit Center, and design review timelines need to be built into the schedule.
- Historic and landmark district design review on exterior changes
- 1900 to 1930 Craftsman framing, often unbolted and uninsulated
- Galvanized supply lines and original wiring replacement
- Rot and joist repair under original bathrooms and porches
- Trim, window and roofline matching so additions read as original
What Your Lot Allows
California ADU law overrides a lot of local restrictions, but the details still matter: setbacks, height limits, fire zones, sewer capacity, and whether your panel can carry a second unit. We walk the property first and tell you what's actually buildable before you spend a dollar on design.
- Zoning and setback review for your specific parcel
- Utility and electrical panel capacity check
- Fire-severity zone and hillside requirements
- Parking replacement rules
2026 State ADU Rules That Save You Money
California law now caps what cities can charge and how long they can sit on your ADU application. These rules come from state ADU law as summarized in HCD's March 2026 ADU Handbook. Building permit, plan check and utility connection fees can still apply, and we confirm the exact numbers for your city at the site visit.
- 750 sq ft or less of interior living space: no impact fees from the city, special districts or water companies (Gov. Code §66324)
- Under 500 sq ft: no school impact fees for ADUs or JADUs
- Over 750 sq ft: impact fees are proportional to the size of your main home
- Complete application: the city has 60 days to approve or deny it (Gov. Code §66317)
How the Project Runs
One team from start to finish. You'll never be the middleman between an architect, a permit expeditor, and a builder, and you'll see the schedule, payments, and job-site photos in your private client portal the whole way through.
- Free site visit and feasibility review
- Design and engineered plans
- LADBS submittal, corrections and approval
- Construction with inspections at each milestone
- Final walkthrough, punch list and warranty
FREQUENTLY ASKED QUESTIONS
Do you do adu & garage conversion in Pasadena?
Yes. Pasadena is part of our regular service area. We'll come out for a free on-site consultation, walk the property, and tell you what's realistic before you spend anything on design.
What does adu cost in Pasadena?
$120,000 – $350,000 depending on size, type and site conditions. Site conditions in Pasadena and your material selections move the number, which is why we price after walking the property rather than over the phone.
Who issues the permit in Pasadena?
Permits for this work go through Pasadena Permit Center. We handle the submittal, plan check corrections and inspections as part of the project.
How much does an ADU cost to build in Los Angeles?
Most detached ADUs in LA run $120,000 to $350,000 depending on square footage, finishes and site conditions. Garage conversions usually come in lower because the foundation and shell already exist. We give you a fixed-price proposal with real specifications after the site visit.
Do I need a permit for an ADU in Los Angeles?
Yes. Every ADU requires permits through LADBS or your city's building department, including plan check and inspections. We handle the entire submittal and correction process for you.
How long does it take to build an ADU?
Once permits are issued, we can complete ADU construction in as few as 120 working days, depending on size, site conditions and finishes. Including design (roughly 4 to 6 weeks) and permitting (6 to 16 weeks), plan on 8 to 14 months total from first site visit to final inspection.
Are impact fees waived for small ADUs in California?
Yes. Under state ADU law, an ADU with 750 square feet or less of interior living space pays no impact fees to the city, special districts or water companies. ADUs and JADUs under 500 square feet also pay no school impact fees. Permit and plan check fees still apply.
How long does the city have to approve my ADU permit?
Once your application is complete, state law gives the city 60 days to approve or deny it. We submit complete, code-checked plans so the 60-day clock starts as early as possible.
Can I convert my garage into an ADU?
In most cases, yes. Garage conversions are one of the most cost-effective ADU paths in Los Angeles because the slab and walls are already there. We check ceiling height, the slab condition, and the panel before recommending it.
Do you build ADUs near me if I'm outside the City of Los Angeles?
Yes. We're the ADU builder homeowners call across a 100-mile radius of our Woodland Hills office, the San Fernando Valley, Ventura County, Orange County and the South Bay included. Detached ADU costs vary with each city's fees and utilities, so we confirm your city's rules at the free site visit.
Similar Projects We've Built
800 sq ft Detached ADU in Encino
A rear-yard detached ADU built for the owners' parents, with its own address, separate electrical sub-panel and a private entry off the side yard.
1,000 sq ft Detached ADU in Northridge
A two-bedroom detached ADU built at the back of a deep Northridge lot, designed to match the main house so it reads as original.
Garage Conversion ADU on Forbes Ave, North Hills
On Forbes Ave in North Hills, a detached two-car garage became a permitted one-bedroom ADU with its own entry, kitchen and laundry hookup.
DISCUSS YOUR PROJECT WITH 1 SMART BUILD
Licensed, bonded and insured design-build general contractor serving Los Angeles County and Southern California. Tell us about your property and goals, and we'll walk you through feasibility, permitting and a clear plan.