large non-wood dog house (Los Lunas)

I adopted a dog from the shelter that ended up growing into being a great Dane. He loves being outside and it’s cold. I built him an enclosure out of straw, but I ended up being allergic to not only the dog, but also the straw the dog needs to be out of something besides wood because he chews on wood. He is a year old, but he still likes to chew. Great Dane dogs are pretty large. He looks more like a greyhound, but he is tall and needs his space. He has a nice large porch to be in, but it’s open on all sides. Or if anybody has the fully enclosed kind made out of metal sides like a fence that would be great.