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Building codes & construction

Occupancy classification

The CBC's use-based grouping of buildings (R-2 apartments, S-2 parking, B office, M retail) that sets height, area, fire, egress and accessibility requirements.

Definition

Occupancy classification is the code's use-based sorting of buildings and spaces into groups — Group R-2 for apartments, R-1 for transient lodging, R-3 for small residential, S-2 for enclosed parking, B and M for offices and retail — under Chapter 3 of the California Building Code. The assigned group, not the marketing label, drives nearly every downstream requirement: allowable height and area, required separations between mixed uses, sprinkler thresholds, egress design, accessibility scope and energy provisions.

Why it matters in an underwrite

A typical podium deal stacks three classifications — R-2 over S-2 parking with M or B space at grade — and each boundary carries separation and protection requirements that belong in the budget from day one. Classification is also where operating strategies quietly change the code: run apartments as short-term rentals (stays under 30 days) and the building drifts from R-2 toward R-1, with hotel-grade life-safety expectations attached.

Sources & related guides

See also

See the term in the law itself

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Last reviewed 2026-07-29. General information, not legal advice.