smoking space in annex

Hello, Our project has a 1-story annex building which is separated from the base building and includes two types of spaces, toilet / shower booth space and smoking room. Both spaces are adjacent each other enlosed by floor to ceiling height partition, and both spaces are exhausted by air outlet fan independently, that makes both rooms negatively pressurized realtive to outdoor ambient. The smoking room exhaust air is isolated from any openings, doors and air intakes to the annex and the base building interior spaces by more than the required distance (25ft). Our question is that: Is it required to measure pressure difference between two rooms, shower / toilet space and smoking room? Any comments are appreciated. Thank you.