If he is use to being inside, why after 3 years would you want him to live outside? I'm assuming that it's because you don't want him to mess up your new home. I personally don't think this is fair to the dog, nor is it safe. Many dogs can dig out of a fenced yard, jump the fence, gate be left open by accident, can be stollen or poisoned, etc. It's just not safe to let a dog outdoors when you are not home or sleeping. Beside that, you don't even know anything about your new neighbors. Kids now days can and will pull all kinds of crap. Try to re-think you decision, please.