Roost door?

[Quetzalcoyote]

I recently built a dutch style coop. I cut a good size arched doorway in the coop. My concern is that the cold air will swirl around in there during these northern winters. My question is should I put some sort of a door that msut be opened and closed manually? Maybe a curtain of some sort? Or should I just leave it open?
Thanks for the help.

 

[ECBW]

I had the same concern when building my coop. So I cut the opening as small as possible (10Wx12H) and installed a door.

As it turned out, the door was never closed. In the worst winter, all other windows and vents would be closed, the door would be the only ventilation.

The door was closed only during a hurricane and when I wanted to keep them out of my way cleaning.