Which License for ADUs, Additions, and Whole-Home Remodels?

For an ADU, addition or whole-home remodel, the General Building (B) classification is often the first license to evaluate because it covers projects that involve at least two unrelated building trades. It is not a shortcut for every specialty: an electrical, plumbing, HVAC, roofing or other specialty scope may require the appropriate classification or a properly licensed subcontractor.

Comparison

Why B is often the starting point

An ADU or whole-home remodel usually combines framing, finish work, roofing, plumbing, electrical or mechanical work. The B classification can fit a contractor who lawfully undertakes and coordinates a project involving at least two unrelated building trades, subject to the exact work and current CSLB rules. Read the CSLB classification descriptions before advertising a scope.

Where specialty classifications matter

If the business only performs one specialty, start with that specialty classification. A C-10 license does not become a B license because the job is in an ADU; likewise, a B license does not authorize every specialty task without considering classification boundaries and subcontracting.

FAQ

Is a B license always required for an ADU?

No. The correct classification depends on the work the contractor undertakes and how the project is structured. A multi-trade prime contractor may evaluate B; a specialty contractor may use the relevant specialty classification.

Can a B contractor self-perform every trade?

Do not assume that. Map the scope to CSLB classifications and use properly licensed specialty contractors where required.

What should I study for B?

Start with CSLB's B study guide and use the Peerless General Building B Study Guide Book.

Sources

• CSLB classification descriptions
• CSLB examination study guides

Peerless Institute has helped California contractors prepare for CSLB exams since 1953. Use the Peerless General Building B Study Guide Book when the B path fits your scope.