keeping coop door open in the winter?

[RAI4]

We currently have 4 hens. I have a small coop I bought, regretfully , and added on to it a small dog house. The run is 6x7. I'm from NJ and I've been keeping the coop door open at night. They are totally protected, but is this ok for the winter?

 

[RAI4]

Here is a pic

 

[jetdog]

Mine closes every night but I have a automatic door on a timer, the less cold air blowing in the better in my opinion, plus not having to go out and open an close the door is just a convince for me, you might want to consider putting clear shower curtains around your run to keep the snow and wind out it would definitely make things more comfortable for them in the winter.

 

[PheasantsFirst]

But it can also provide ventilation, Thought it may be too much.

 

[RAI4]

Thanks. I did put some plastic up.