So, I was rasied a city gal. My parents motto, "Pets belong in the house with their family". Admittedly, I have carried this motto as well, 2 labs, 1 husky, 4 cats, and 1 rabbit all snuggled up by the fire on those cold winter nights! When we decided to get chickens and I asked my husband how we were going to heat the coop, he laughed at me and told me chickens have lived successfully in drafty old barns for years... they will be fine in a well vented coop. It may have been the threat of bringing them in the house that spawned the solar radiant heat. We built the coop entirely out of used and, might I add free materials with the exception of piping, fittings, and insulation. This was our goal when we set out, so we were pretty excited with the finished product. I had a few questions from others about the coop, so I though I'd post some pictures. In the winter the sun shines on the solar panels, which heats the liquid that runs through the tubes. The liquid circulates, radiating the heat through the floor. At night, we have some bricks and things that hold the temperture and continue to radiant heat. Last year the average temperature in the coop was 35. This year we are adding more mass to absorb the heat and increase the average temperature. All without an increase in the electric bill!