Oh yes, you for sure want it in the ceiling or all your heat will go right out the top since heat rises. We have very thick insulation in all walls and the ceiling and now I wished I would have put it in the floors as well. That way I would not have to put anything around the bottom of the hen house every winter. Good luck with your hen house. We just got done with a double hen house where there is hardware cloth in the middle to separate each bunch. I have D'uccles on one side and orps on the other. You can see pics of it on my website if your interested. You will have to scroll down for the pics.