Here’s what Compton's Interactive Encyclopedia (© 1998 The Learning Company, Inc.) has to say about housing rabbits:

"If you keep your rabbit indoors, cut a door in a grocery box for its house. Put shavings on the floor and change the soiled ones every day. You can housebreak a rabbit by always putting papers in the same place, near its nest. Do the same as you would for a dog or cat. The bunny will make a mistake now and then, so be patient.

"For living outdoors, the hutch for one rabbit should be at least three feet long and a foot and a half wide and high. Partition a sleeping place in one end. Set the hutch on posts. Cover all the floor with shavings, sawdust, or hay and keep it dry. Scrub the hutch once a week. Your pet should have an outdoor run enclosed by fine-meshed wire netting set at least two feet into the ground to prevent burrowing. In summer, shade the hutch."
If you're keeping your bunny in a hutch, try to make it face the morning sun, not the afternoon sun.