Do rooftop enclosures for elevators require a Fire Resistance Rating (FRR)?

Rooftop enclosures for elevators do not require a Fire Resistance Rating (FRR) if they are not more than one storey in height. This requirement stems from building codes that differentiate between structures based on their size and height. Generally, the fire safety requirements are more stringent for taller structures, which is likely tied to the increased risk of fire spread and the need for occupant safety during evacuation.

In the case of enclosures that are restricted to a single storey, the regulations often recognize that the risk is lower, thereby allowing for simpler construction methods that do not necessitate fire-resistive construction. This aligns with broader principles of building safety, which focus on proportionality in the application of fire safety measures.

Thus, for enclosures above one storey, additional considerations come into play, including whether they are made of combustible materials or their overall height, which may invoke different requirements regarding fire ratings. This is why choosing the option that specifies no requirement for enclosures of only one storey is correctly understood, as it reflects the intent and structure of fire safety regulations.