Rocket Mass Heater Space

I am planning to build a house and am working on floor plans. Without getting into too much detail of types of rocket mass heaters, is there a good general guideline of how much space I should allocate for a "typical" (if there is such a thing) rocket mass heater?

Thanks,

John

Hi John;
It all depends on what you want.  
You can have a long bench to sit on or a tall / odd shaped bell  (big brick box) to sit near.
You will want your rmh in the center of your floor and away from outside walls if possible. Whatever type you choose.
Your chimney type and location will have a bearing as well.