Windowless Rooms in Accordance with BS 5266 and Fire Safety Approved Document B

Understanding BS 5266 in Conjunction with Fire Safety Approved Document B for Windowless Rooms

Regarding the statement in Approved Document B fire safety volume 2-Buildings other than dwellings, Table 5.1

It states that “Areas requiring escape lighting” and includes “Underground or Windowless accommodation”

It is the view of Philip Payne that:

Accommodation is defined as ‘a room, group of rooms, or buildings in which someone may live or stay’, therefore it includes any room that is regularly occupied, such as offices, hotel bedrooms, classrooms, laboratories etc. but not include walk in cupboards, storerooms less than 60m² or any other room that is not routinely occupied.

Philip Payne considers that underground or windowless, covers any space without a reliable source of borrowed light as according to BS5266-1:2016, 3 Terms and definitions, 3.1 borrowed light.

“Light obtained from an adjacent reliable source that is expected to be available at all material times.”

NOTE: For example, from a local emergency luminaire

Defining Emergency Escape Lighting BS5266-1:2016, 3 Terms and definitions, 3.5 emergency escape lighting, States:

“That part of emergency lighting that provides illumination for the safety of people leaving a location or attempting to terminate a potentially dangerous process before doing so.”

Therefore in summary: any room that is regularly occupied and does not have borrowed light would need suitable emergency escape lighting.

The occupants should be provided with suitable escape lighting until they reach a planned place of safety.

For example, the escape route would have minimum 1 lux on the centreline, with minimum 0.5 lux on half the width of the route