The primary function of corridor and stairwell lighting is not aesthetics—it is life safety. Failing to achieve Office Compliance in these critical transit zones violates the Regulatory Reform (Fire Safety) Order 2005 and places corporate directors at risk of prosecution.
1 Lux Minimum on the Escape Route Centre Line
During a mains power failure, BS 5266-1 dictates that emergency lighting must provide a minimum of 1 Lux anywhere along the centre line of the designated escape corridor.
In a smoke-filled office corridor, panicked staff need a clear, continuous path to the fire exit. If emergency bulkheads are spaced too far apart, dark patches form between the lights. Someone running through a dark patch may trip over fallen debris. Photometric planning is required to prove that the light cones from the emergency LEDs overlap sufficiently to guarantee 1 Lux is never broken.
Points of Emphasis (Stairs and Changes of Level)
BS 5266-1 specifically mandates that an emergency luminaire must be placed within 2 meters horizontally of any "Point of Emphasis," including every flight of stairs, change of direction, or fire alarm call point.
You cannot simply place one light at the top of a stairwell and hope the light bounces down. A dedicated emergency light must directly illuminate every single tread and the high-contrast nosing on the steps. If the stairwell turns a corner, another light must be placed to illuminate the landing. This ensures that evacuees do not misjudge the stairs and cause a fatal pile-up.
Microwave Sensor (PIR) Corridor Step-Dimming
To balance safety with energy efficiency, office corridors should utilize microwave sensors configured to "Step-Dim," holding the lights at 10% standby, instantly ramping to 100% (100 Lux) upon detection.
Leaving office corridors blazing at 100% all day when nobody is walking down them is a massive waste of electricity. However, having them turn completely off is dangerous, as a staff member stepping out of an office into a pitch-black corridor can suffer a slip/trip before the sensor activates. Step-dimming ensures the corridor is never entirely dark, maintaining baseline safety while slashing energy use by 80%.