| Primary value | 150 mm |
| Applies to | Schools and educational buildings · Hospitals · Office buildings · Cinemas, halls, places of assembly · Hotels |
| Exceptions | Residential individual house → 190 mm allowed |
| Measured as | Vertical step height between consecutive treads. |
| Source | NBC 2016 — Part 4, Clause 4.4.2 ✓ Verified |
Public buildings serve a wide range of users — children, elderly, infirm, occasional users unfamiliar with the building. The 150 mm maximum gives a gentler climb that all these users can handle safely without missteps.
Public stairs typically use 130–150 mm risers. This is also the standard for hotel stairs, where guests use the stair only occasionally and expect gentle proportions.