ADU Construction in Los Angeles
Design-Build or Build From Your Plans
- Design-build: from idea to keys. You bring the goal and the lot. We design the unit, prepare the engineering, pull the permits, and build it, with one contract and one point of contact from start to finish. Best for owners starting from scratch.
- Build-only: construction from your plans. You already have drawings from an architect or designer, or a pre-approved standard plan. We price the construction line by line from your plan set, handle any permits still outstanding, and build what is drawn. Best for owners who invested in design and need a licensed contractor to deliver it.
What You Can Build on Your Lot
- Detached ADU. A standalone backyard home, typically up to 1,200 square feet. The biggest rent and resale upside.
- Attached ADU. An addition built onto the main house with its own entrance, kitchen, and bath.
- Garage conversion. The existing structure becomes a living unit. The fastest, lowest-cost path to a rentable ADU.
- Junior ADU (JADU). Up to 500 square feet carved out of the existing home, with an efficiency kitchen.
Why Now Is the Easiest Time to Build an ADU in California
- Cities must act on a complete ADU application within 60 days.
- Side and rear setbacks are capped at 4 feet. There is no minimum lot size.
- Impact fees are waived for ADUs under 750 square feet.
- No owner-occupancy requirement. You can build an ADU and rent it out without living on the property.
- Los Angeles runs a Standard Plan Program with pre-approved ADU designs that cut review time.
The CalPrime ADU Process
Feasibility and planning
We review your lot, existing structures, utilities, and goals, then map the options with honest numbers.
Design and documentation
Our team prepares plans built for livability, rental demand, and code compliance.
Permits and city coordination
We submit, answer plan-check comments, and pull the permits.
Construction and oversight
Our crews build from foundation to finishes with tight quality control, and we keep you on budget and on schedule
What Drives ADU Cost in Los Angeles
- Lot and site: slope, soil, access, and utility runs
- Size and type: a garage conversion costs a fraction of a new detached build
- Permits and approvals: city fees, plan check, and fire sprinkler requirements where they apply
Finish level rounds it out. We give you a line-item estimate before you commit, and the number we quote is the number we build to.
Most owners look at the cost next to the return: LA rents are among the highest in the country, and a well-built ADU keeps paying through rent and resale value.
Why Build Your ADU with CalPrime
- One accountable team either way: full design-build under one contract, or construction from the plans your architect drew.
- Structural work is our specialty. We retrofit buildings for a living, so your ADU's foundation and framing get the same attention as a seismic project
- Licensed, bonded, and insured. CSLB License #1141734.
- Offices in Los Angeles and Newport Beach, building across LA and Orange County.
- Clear budget, clear schedule, and straight answers before you sign.
ADU FAQs
Yes. Every ADU needs approved plans, permits, and inspections. The upside: state law requires cities to approve complete, qualifying applications within 60 days, and LA’s Standard Plan Program can shorten that further. Unpermitted units invite fines and create problems when you sell or refinance.
Yes. We price construction straight from your plan set, flag anything that will not pass plan check or field inspection before work starts, and build what is drawn. If your permits are already issued, we mobilize even faster.
Plan on 2 to 4 months for design and permits. Construction then runs about 2 to 3 months for a garage conversion and 4 to 6 months for a new detached unit. Arriving with finished plans shrinks the front end to plan check and permits.
Yes, on leases of 30 days or longer. California no longer lets cities require you to live on the property, so an ADU can be a straight rental investment.