ADU Construction in the Bay Area: What to Expect

An ADU — accessory dwelling unit — is one of the most practical ways to add usable space and flexibility to a Bay Area property. Whether it's a rental, a place for family, or a quiet home office, here's what building one actually involves.

The main types of ADU

• Garage conversion — turning an existing garage into a living unit. Often the fastest path since the structure already exists.
• Detached (backyard) ADU — a standalone unit built in the yard. The most private and flexible, and the most involved to build.
• Attached ADU — a unit added onto the existing house with its own entrance.
• Junior ADU (JADU) — a smaller unit created within the existing home's footprint.

How the process works

• Feasibility — we look at your lot, setbacks, utilities, and what your city allows.
• Design — a layout that fits the space and how you'll use it, plus the drawings for permitting.
• Permits — prepared and submitted; California and many Bay Area cities have streamlined ADU approvals in recent years.
• Construction — foundation (for detached), framing, utilities, and finishes, managed by our own crew.

What to plan for

The biggest variables are the type of ADU and your site. A garage conversion reuses an existing structure and moves faster; a detached unit needs a new foundation and utility runs and takes longer. Utilities (water, sewer, electrical) and your lot's setbacks shape what's possible. We sort all of that out during design so there are no surprises once we start.

How we work

Genesis is a licensed general contractor (CA #1052900), 5-star rated on Google and Yelp, with 12+ years and 500+ projects across San Francisco, the Peninsula, and the South Bay. We handle the ADU from feasibility through permits to the final walkthrough, with our own crew and honest, itemized proposals.

Thinking about an ADU? Book a free, no-obligation consultation and we'll walk your property and lay out your options. Call (800) 950-3984 or reach us through our contact page.