ADU Builders in San Carlos, California
With about 30,000 residents and housing costs that keep climbing, San Carlos homeowners are turning backyards into income. Our San Carlos ADU builders handle design, San Mateo County-area permitting and construction under one contract, built for the cool microclimates, fog belts and seismic activity.
Typical cost
$235k–$489k
Permit time
4–8 weeks
Est. rent
$2,450+/mo
Population
30,000
Popular ADU types in San Carlos
Our most requested projects in San Carlos are two-story ADUs over garages and detached backyard cottages. Corner lots and alley-access lots in San Carlos are ideal for ADUs with their own street entrance and separate address.
Design-wise, San Carlos 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 San Carlos 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 $2,450–$3,950 per month in rent, a new ADU in San Carlos can pay for itself in roughly 9.4 years.
San Carlos ADU FAQs
How much does it cost to build an ADU in San Carlos?
Most San Carlos ADUs we build land between $235k and $489k, 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 San Carlos?
State law requires cities to act on complete ADU applications within 60 days. In practice, San Carlos 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 San Carlos?
Based on Bay Area rental trends, a new 1-bedroom ADU in San Carlos commonly rents for $2,450–$3,950 per month, putting typical payback around 9.4 years.
What are the biggest challenges for ADUs in San Carlos?
In San Carlos 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 two-story ADUs over garages a good option in San Carlos?
Yes — two-story ADUs over garages are among the most popular projects we build in San Carlos. Across San Carlos, we see strong demand for 1-bedroom units around 600 sq ft — the sweet spot for build cost versus rental income.
ADU builders near San Carlos
Get a free ADU feasibility check in San Carlos
Tell us about your lot. We'll review zoning, setbacks and utilities and send a ballpark budget — no obligation.