My dog spent the first 5 years of his life being chained in a yard with a dog house. When he was rescued by a young couple, for some strange reason they brought the dog house with them and decided he'd be happier outside since that was how he was used to living. Not chained any more, but outside nonetheless where they felt he was conditioned to live. They also thought he'd get too hot in the house. Imagine their surprise when the dog spent every waking moment plastered to their back door whining to come inside with them!
After a few days they got the hint and let him come inside with them and the other 2 "inside" dogs.
Today, my 100 lb goofy boy lives in a Strata complex with no yard and he's inside with the family 24/7. If the front door is open on a hot day, he lies inside the house with his paws hanging over the step and he refuses to go out unless we are with him. In fact, he won't even lie out on the deck unless I'm out there reading or something. Smart dog, he knows where he wants to be:)