| Primary value | 10 lux |
| Applies to | Stair landings, exit corridors, fire escape routes |
| Exceptions | Open areas (assembly, offices) → 10 lux floor illuminance min |
| Exit signs → Internally illuminated — readable from 30 m | |
| Battery backup duration → ≥ 90 minutes | |
| Open areas > 60 m² (anti-panic lighting) → Minimum 5 lux at floor level | |
| Escape route edges (for routes up to 2m wide) → 50% of the route width must be lit to a minimum of 5 lux | |
| High-risk task areas (e.g., control rooms, plant rooms) → 10% of normal lighting illuminance, but not less than 15 lux | |
| Measured as | Illuminance at floor level along escape route, measured during a simulated mains failure. |
| Source | NBC 2016 — NBC 2016, Part 8, Section 2, Clause 5.7.3 ✓ Verified |
During a power failure, which is common during fires or other emergencies, adequate lighting is critical for preventing panic and ensuring occupants can safely navigate escape routes. NBC 2016 mandates this minimum illuminance to ensure visibility of obstacles, changes in level, and exit signage, facilitating a swift and orderly evacuation.
Typically, self-contained LED emergency luminaires with a minimum 90-minute battery backup are installed. These are strategically placed at changes in direction, corridor intersections, stair landings, and directly above final exit doors to meet the code's requirements for 'points of emphasis'.