Under annunciation rules, can a floor exceeding 20,000 sq ft be treated as a single zone?

• A. True
• B. False
• C. Not specified
• D. Only for floors exceeding 50,000 sq ft

Answer: (A)

Large spaces are often grouped into a single annunciation zone to keep alarm notices clear and manageable. When a floor exceeds a substantial size, treating it as one zone helps responders quickly identify the general area without being overwhelmed by many small zones. If the open floor plan or occupancy means a single point of origin is reasonable, using one zone avoids fragmentation that could slow response. The threshold of 20,000 square feet is used in this context as a guideline to decide when one zone is appropriate. If there are distinct, independent areas within that floor that would require separate monitoring or would benefit from isolating a portion of the space, then subdividing into multiple zones would be more appropriate.