National baseline
Start with the National Plumbing Code fixture count tables organized by occupancy and occupant load.
Canadian building code question
The required plumbing fixture count depends on the building's occupancy classification, the occupant load for each area served, the fixture ratio tables in the applicable plumbing code, gender ratio assumptions, and how the province adopts or amends the national model codes.
Plumbing fixture counts are driven by occupant load and occupancy type, but the calculation path can branch depending on whether the province references the National Plumbing Code directly, uses a modified version, or references a different standard altogether. Gender-neutral washroom provisions have also introduced changes in some jurisdictions. The safest approach is to confirm the occupancy, calculate the occupant load, then verify the applicable fixture table.
Start with the National Plumbing Code fixture count tables organized by occupancy and occupant load.
Confirm how the province adopts the NPC and whether local plumbing codes or bylaws modify the fixture count requirements.
Occupancy type, occupant load, gender ratio assumptions, accessible fixture requirements, and whether gender-neutral provisions apply can all affect the count.
No. The fixture ratio tables specify different counts for different occupancy types. Assembly, business, mercantile, and institutional occupancies can have different fixture requirements.
In some jurisdictions, yes. Gender-neutral provisions can change how fixtures are counted and allocated, potentially reducing the total number while maintaining access.
Barrier-free fixtures are typically required in addition to or as part of the base fixture count, depending on the code provision. They are not usually an extra beyond the calculated total but must meet accessibility dimensions.