The group shelter offers comfortable winter protection that no tent could ever match. In addition, you don't feel the bite of the wind.
Make it as small as possible to save on materials and keep in the warmth. The diameter of the central opening must be small enough to trap the heat of the fire without becoming a safety risk. Most people make the opening too large.
A doorway helps provide the draft to draw the smoke upwards. This shelter can provide a good home for weeks on end.