I'm building classrooms in the large basement of our home; we're in Spain and have an English school we're expanding.
Room to room sound insulation and resonance are the major concerns I have to consider, as well as costs. The actual ceiling is over three metres high and I plan on using acoustic ceiling tiles to help with echo, which currently is a major issue.
Does it make sense to build dry wall, say, two and a half metres tall with suspended ceiling lowered inside and insulated above with glass wool or similar? That would mean there would be a large open space above the classrooms which would be sound insulated from below. This would save (insulated) dry wall costs and glass wool is pretty cheap.