Accessory Dwelling Units — ADUs — have exploded in popularity across Los Angeles. California’s pro-ADU legislation has made it easier than ever to add a rental unit, in-law suite, or guest house to your property. But the process still involves permits, design, and construction — and missteps can cost you months and thousands of dollars.
This guide walks you through every step of adding an ADU in Los Angeles in 2026.
What Is an ADU?
An ADU (Accessory Dwelling Unit) is a secondary housing unit on a single-family or multi-family lot. In Los Angeles, ADUs come in several forms:
- Detached ADU — a standalone structure in the backyard
- Attached ADU — built onto the side or rear of the main house
- Garage conversion ADU — existing garage converted to living space
- Junior ADU (JADU) — unit within the existing home, up to 500 sq ft
Step-by-Step: How to Build an ADU in Los Angeles
Step 1: Determine What You Can Build
In LA, most single-family lots can now have 1 standard ADU, 1 Junior ADU (JADU) within the existing home, and additional ADUs on lots with existing multi-family buildings. Key rules for detached ADUs: maximum 1,200 sq ft, 4 ft side and rear setbacks, 16 ft height limit.
Step 2: Hire a Licensed Contractor and Designer
Your ADU needs architectural plans before you can pull permits. Working with a design-build contractor like Cali View Builders who manages both saves time and reduces coordination headaches.
Step 3: Submit Plans to LADBS
All ADUs in Los Angeles require a building permit from LADBS. You’ll submit architectural plans, a Title 24 energy compliance report, structural calculations (if required), and permit application and fees. LA now offers an Express ADU Permit program for pre-approved standard plans.
Step 4: Permit Approval and Plan Check
Standard plan check takes 4–12 weeks at LADBS. Using pre-approved plans can cut this to 2–4 weeks. Your contractor handles any correction responses during this phase.
Step 5: Construction
| ADU Type | Construction Timeline |
|---|---|
| Garage conversion | 6–12 weeks |
| Attached ADU | 10–16 weeks |
| Detached ADU (new construction) | 14–24 weeks |
| Junior ADU (within existing home) | 4–8 weeks |
Step 6: Inspections and Certificate of Occupancy
LADBS inspectors visit at key milestones — foundation, framing, rough plumbing/electrical, insulation, and final. Once all inspections pass, you receive a Certificate of Occupancy.
ADU Cost in Los Angeles: 2026 Estimates
| ADU Type | Cost Range | Notes |
|---|---|---|
| Junior ADU (JADU) | $40,000–$90,000 | Lowest cost — uses existing structure |
| Garage conversion | $80,000–$160,000 | Depends on garage condition |
| Attached ADU (500 sq ft) | $120,000–$200,000 | Shares wall with main house |
| Detached ADU (800 sq ft) | $180,000–$320,000 | Full standalone structure |
| Detached ADU (1,200 sq ft) | $280,000–$480,000 | Largest standard size in LA |
ADU Financing Options
- Cash-out refinance — tapping home equity at a fixed rate
- HELOC (Home Equity Line of Credit) — flexible draw as needed
- Construction-to-permanent loan — converts to mortgage at completion
- CalHFA ADU Grant — up to $40,000 for income-qualifying homeowners
Can I Rent Out My ADU?
Yes — a 1-bedroom ADU in North Hollywood or the San Fernando Valley can rent for $1,800–$2,800/month. You cannot use an ADU for short-term rentals (Airbnb, VRBO) under most LA zoning rules unless you live on-site and have a city-issued short-term rental permit.
Why Work With Cali View Builders?
Cali View Builders has built ADUs and converted garages throughout Los Angeles. As a licensed general contractor (CSLB #1081371), we manage everything from initial design consultation through final inspection.
- In-house design coordination — one point of contact
- Extensive LADBS permit experience
- Garage conversions, detached ADUs, JADUs, and attached additions
- Serving North Hollywood, Van Nuys, Burbank, Glendale, Pasadena, and greater LA
Get a Free ADU Consultation
Ready to find out what ADU options your lot can support? Call (323) 484-8458 or visit caliviewbuilders.com to schedule your free ADU consultation today.