Materials still to be decided; I can’t use pressure treated wood on any plane/surface that Ginger would touch because of the chemicals in the treated wood. I read a lot of research on this topic in the evenings after the office hours of my summer internship, and one of the biggest issues is insulation (I have looked at SIPS for a combination of structure and insulation); if the doghouse doesn’t provide a functional space that keeps my dog out of the cold, it’s a useless box in the back yard and is little different from front yard lawn gnome furniture.