Damn, this sounds very similar to our situation 10 years ago! What are the rules on a 2-stage system?
At the time, my high school was putting on expansions and like yours, construction set it off regularly. My school pretty much decided to just deal with it. In the state I was in at the time, they only had to do 3 fire drills / year, and accidental activation of the system counts toward those. They pretty much considered these false alarms to be drills for both us and the fire department.