Building Occupant Load from Area and Use (IBC Table 1004.5)

The occupant load = sum over spaces of ceil(area / occupant-load factor). The factor is set by how the space is used, not its label - a 3,000 ft^2 office at 150 ft^2/occ is 20 people; the same floor as a standing bar at 5 ft^2/occ is 600. Bundled representative factors (business, assembly, mercantile, classroom, kitchen, industrial, storage, residential) are editable defaults; the factor and its net-vs-gross basis come from the AHJ-adopted code edition. A design aid, not a code-official determination.

per_space_load = ceil(area / olf); total_load = sum over spaces of per_space_load.

IBC 2021 §1004.5 and Table 1004.5 (occupant load = area / occupant-load factor, summed over spaces) and §1004.2 (round up to a whole person), by name.

The occupant-load relation is stated in the published IBC §1004.5; the arithmetic is public. The occupant-load factors are the Table 1004.5 values for the actual use.

Estimate. AHJ and licensed professional govern.

Field names used by the API: spaces, total_load, space_count

• Per-space load ceil(area / occupant-load factor) per §1004.2 rounds each space up to a whole personIBC 2021 §1004.5 / §1004.2
• Total the occupant load is the sum across spaces; the use, not the area alone, governs the factorIBC 2021 Table 1004.5
• Factor source the bundled factors are representative defaults; the AHJ-adopted edition and the actual use set the governing factor and its net-vs-gross basisIBC 2021 Table 1004.5