I'd physically built a small version, and unfortunately heavier version of this one.
This one uses 1.5" insulation board to insulation all sides. The front entrance isn't insulated, but the interior wall to the den area is. Lots of things a person could do to baffle the entrance in the winter. The idea i laid out in this one gives the dog a place to lay and look out. 2x2 or ripped 2x4 frame construction. More rigidity comes from construction adhesive used in the plywood to insulation sandwich.
Roof: Up to you. I'd use steel sheeting with j-channel on the top and 2 sides, leaving water to fall the back. Felt and shingles with a little roofing caulk would work well too.
Hope you like it.
Always happy to hear feedback.
#canine #dog #doghouse #house