If you are planning on insulating, I probably wouldnt worry about heating it even with one heat lamp. I didnt use any last year and they did great and we had a seriously bad winter with all the snow we had. Your coop will be small enough that their body heat should keep it pretty warm.
BUT, if...
I can see how I didnt make sense.
The reason I do not do heat lamps anymore is that the heat is centralized around the light bulb which makes one area in the coop alot warmer than a nice uniform heat throughout in my opinion. When I did it before, the birds would huddle near the lamp, which can...
I have a few things to say about the coop in winter.
First of all, Chirpy, seeing you are in Colorado too, I know what kind of weather you will have so I will just describe what I have done and dont do anymore.
I have had chickens for about 5 years now. Our coop was very insulated in the...