My little rex lives happily in his hutch/run but he had a very deep layer of straw/hay and his run is always on grass. I would say this for rexes - have had various types of bun in the past but rexes are full of character. He's so much 'larger than life' - a real little funny personality. He's lively and friendly, and I understand from other people this is typical. They're fantastic buns! But maybe not a house bun?