We are doing a building where half the building is offices and the other half is workshops for parks maintenence staff. (I'm talking mechanical, carpentry, tree crew). These rooms have 2 Hollow Metal doors and one roll-up door each. Is there any way to argue that only the office half of the building needs these measures? I can't imagine MERV 13 and sawdust are a good combo. 

I was planning on putting a walk-off mat at the door between the workshops and the offices.