Simplified Approach

I have a kindergarten, 7440sf, ground level only, all learning spaces are on perimeter with windows. There is only a small road on the one side about 20 m away. There is no Mechanical Ventilation, just a radiant floor heating. The mechanical room is not adjacent to any learning space. All learning spaces have acoustic ceiling tiles with NRC 0.65, covering >80% of the ceiling. Ceiling height is at about 3.2 meters. The floor is laminated, and has a 8mm (3 inch) wood fiber board "Trittschalldämmung" Step absorption layer. I've just been told we're not getting the usual acoustics calculation, because it was no longer required. This leaves me to do this on my own. Q1) will it be accepted to do the calculation for one representative room? (there are 9 "learning" spaces) Q2) Are other spaces, like corridors to be included? Any other hints, suggestions and tips are appreciated. Good page btw.