| Primary value | 1 per 25 persons |
| Applies to | Office buildings · Mixed-use workplaces |
| Measured as | Provide 1 wash basin for every 25 occupants (regardless of gender). |
| Source | NBC 2016 — Part 9, Section 2 ⚠ Clause pending verification |
Wash basins are essential after WC use for hygiene. The 1:25 ratio is more generous than WCs because basin use is faster — quick handwashes don't accumulate queues.
Most offices install 1-2 basins per restroom regardless of strict count, especially after COVID-era hygiene awareness.