CaliCustomADU

ADU Builders in San Jose, California

Families across San Jose are using accessory dwelling units to solve multigenerational living and generate rental income. As full-service ADU builders, we take San Jose projects from feasibility to final inspection — designed for the cool microclimates, fog belts and seismic activity.

Typical cost

$245k–$510k

Permit time

8–14 weeks

Est. rent

$2,550+/mo

Population

970,000

Free San Jose ADU estimate

Popular ADU types in San Jose

Our most requested projects in San Jose are prefab and modular ADUs and attached ADUs. Newer subdivisions in San Jose often have tighter side yards, so we frequently recommend attached ADUs or converting an existing garage to keep costs down.

Design-wise, San Jose homeowners in the Bay Area tend to favor compact, light-filled modern designs that maximize small urban lots.

Building an ADU in Santa Clara County

Every San Jose 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 8–14 weeks here.

At $2,550–$4,100 per month in rent, a new ADU in San Jose can pay for itself in roughly 9.5 years.

San Jose ADU FAQs

How much does it cost to build an ADU in San Jose?

Most San Jose ADUs we build land between $245k and $510k, 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 Jose?

State law requires cities to act on complete ADU applications within 60 days. In practice, San Jose permits typically take 8–14 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 Jose?

Based on Bay Area rental trends, a new 1-bedroom ADU in San Jose commonly rents for $2,550–$4,100 per month, putting typical payback around 9.5 years.

What are the biggest challenges for ADUs in San Jose?

In San Jose 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 prefab and modular ADUs a good option in San Jose?

Yes — prefab and modular ADUs are among the most popular projects we build in San Jose. Corner lots and alley-access lots in San Jose are ideal for ADUs with their own street entrance and separate address.

ADU builders near San Jose

Get a free ADU feasibility check in San Jose

Tell us about your lot. We'll review zoning, setbacks and utilities and send a ballpark budget — no obligation.