Accessory Dwelling Units remain one of the highest-value additions a Los Angeles homeowner can build — extra rental income, space for family, or a home office. Here's what they actually cost in 2026.
Detached ADU (New Construction)
A new detached ADU in LA typically runs $150,000–$350,000+ depending on size (400–1,200 sq ft is common), foundation type, and finish level.
Garage Conversion ADU
Converting an existing garage is usually the most cost-effective path, often $90,000–$180,000, since the structure, foundation, and roof are already in place.
Junior ADU (Attached)
A JADU carved out of existing living space (with its own entrance and kitchenette) is typically the least expensive option, often $40,000–$90,000.
What Drives the Cost
- Size and number of bedrooms/bathrooms
- Utility connections (separate electrical panel, water, sewer lateral)
- Site access for construction equipment
- Finish level (builder-grade vs. custom)
Permitting Timeline
LADBS has streamlined ADU plan review compared to custom homes, but timelines still vary by workload. See our permit process guide for what to expect.
Get a Real Number for Your Lot
Every lot has different setback, zoning, and utility considerations. Contact Green Rise Builders or call (310) 757-3033 for a free ADU feasibility assessment.
Related reading: home remodel cost guide · how LA permitting works