ADU Builder — Bay Area & Northern California
ADUs are the highest-return construction project most California homeowners can build — but only if the ADU is designed for the site, permitted correctly, and built to the same standard as a custom home. That's what we do.
Detached, Attached, and Garage-Conversion ADUs
We build 400–1,200 sq ft detached ADUs, attached ADUs off existing homes, and full garage-to-ADU conversions. Each project is fully permitted, engineered for California code, and finished to match your primary home.
Permit-First Process
California SB 9 and statewide ADU legislation have streamlined approvals, but local jurisdictions still vary widely. We handle the entire permit process — planning, building, utility connections, and any HOA review — so you don't chase paperwork.
Rental Income, Multi-Gen Living, or Home Office
Whether your ADU is a rental, a guest house, a home office, or space for aging parents, we design the floorplan and finishes around the actual use — not a stock plan.
Get a free estimate for your adu design & construction project.
Answers to the questions we hear most.
How much does an ADU cost to build in Northern California?+
Custom ADUs in Northern California typically run $350 – $650 per square foot turnkey. A 600 sq ft detached ADU generally lands between $250,000 and $400,000 including design, permits, and utility connections. Garage conversions are often less because the shell already exists.
How long does an ADU take from start to finish?+
Design and permits typically take 3–5 months; construction runs 4–7 months. Total from signed design agreement to occupancy is usually 7–12 months.
Can I use the ADU as a rental?+
Yes. California law allows ADUs to be rented separately from the main home in nearly every jurisdiction. Short-term rentals (under 30 days) are city-dependent — we'll flag your local rules during design.
Do I need a separate meter or utility connection?+
Sometimes. Attached ADUs and garage conversions can often share utilities; detached ADUs frequently need a separate electrical panel. We handle the utility coordination as part of the build.
"Discipline you can feel in every finished detail."
Every project we finish becomes a reference for the next one. Read what our clients say.
Read Client Reviews