ADU Builders in Millbrae, California
Families across Millbrae are using accessory dwelling units to solve multigenerational living and generate rental income. As full-service ADU builders, we take Millbrae projects from feasibility to final inspection — designed for the cool microclimates, fog belts and seismic activity.
Typical cost
$265k–$551k
Permit time
4–8 weeks
Est. rent
$2,750+/mo
Population
23,000
Popular ADU types in Millbrae
Our most requested projects in Millbrae are detached backyard cottages and two-story ADUs over garages. Newer subdivisions in Millbrae often have tighter side yards, so we frequently recommend attached ADUs or converting an existing garage to keep costs down.
Design-wise, Millbrae homeowners in the Bay Area tend to favor compact, light-filled modern designs that maximize small urban lots.
Building an ADU in San Mateo County
Every Millbrae ADU we build is engineered around local conditions — especially seismic engineering, sewer lateral rules and high labor costs. We prepare complete plan sets so the city can approve within the state's 60-day review window, typically 4–8 weeks here.
At $2,750–$4,450 per month in rent, a new ADU in Millbrae can pay for itself in roughly 9.4 years.
Millbrae ADU FAQs
How much does it cost to build an ADU in Millbrae?
Most Millbrae ADUs we build land between $265k and $551k, depending on size, site work and finishes. Garage conversions sit at the low end; custom two-story units at the high end.
How long does ADU permitting take in Millbrae?
State law requires cities to act on complete ADU applications within 60 days. In practice, Millbrae permits typically take 4–8 weeks when plans are submitted complete — which is what our in-house drafting team focuses on.
What can I rent an ADU for in Millbrae?
Based on Bay Area rental trends, a new 1-bedroom ADU in Millbrae commonly rents for $2,750–$4,450 per month, putting typical payback around 9.4 years.
What are the biggest challenges for ADUs in Millbrae?
In Millbrae and the wider Bay Area, the issues we plan around most are seismic engineering, sewer lateral rules and high labor costs. We review these during a free feasibility check before you commit.
Is detached backyard cottages a good option in Millbrae?
Yes — detached backyard cottages are among the most popular projects we build in Millbrae. Corner lots and alley-access lots in Millbrae are ideal for ADUs with their own street entrance and separate address.
ADU builders near Millbrae
Get a free ADU feasibility check in Millbrae
Tell us about your lot. We'll review zoning, setbacks and utilities and send a ballpark budget — no obligation.