House Training a Dog That Won't Poop or Pee Outside?

My husband's dog is still going to the bathroom in the house. He has free access to a decent size yard, but refuses to go off the deck. He has never had any bad incidents to our knowledge. It has been many months since my husband and I have been married and my children and I moved in and he still refuses to go to bathroom outside.

I do not like our house smelling like a litter box. He goes for walks and won't do anything, but immediately when we get home he will go off by himself and poop or pee. It is frustrating. My husband is very close to his dog, but I am at my wits end putting up with his bad behaviour. ( You can tell who has to clean up the mess).

By javamom77 from Medicine Hat, Ab