I know this won't be popular, but Sancho is not allowed in the carpeted areas of the house, on the furniture, and especially not in our bed/bedroom. It's not because we're mean (really), it's mainly due to my severe allergies to his dander. Plus, I'm a type-A super neat freak and I think I would go insane with allergies AND messes. More than half our home is tiled, so he still has access to a good portion of the house.
So far, this hasn't been an issue, as we've never given him that space and then taken it back. He has never been in those areas and knows he's not allowed. It may become harder as he gets older, but we're going to hold our ground. The only way I can see this POSSIBLY changing is if we decide to re-floor the house and ditch the carpet. Even then, though, no furniture.