Control room, vocal booth and drum booth room size standarts

Hi everybody, I wanna ask that if anybody knows that if there's an international standart about the size of a studio's control room, vocal booth and drum booth? Or any minimum/maximum size standards for these rooms? Is it okay that If I build a 7mt2 vocal booth to record little choir? Is It okay that If I build a 20mt2 drum booth to have 2 different drum kits inside to record? (not at the same time of course) I mean how big can it be? :-) Thanks and cheers..

7m2 seems a bit small for a choir, and 20m2 while nice for a drum booth may be a better size for a choir... why not just make the 20m2 booth flexible enough for both and just move equipment in and out as needed?