Environment
There are multiple options you can choose to house a rabbit, just make sure they are safe from harm, always have fresh food and water and have enough room to jump around.
Free Range: Some people choose to give their rabbit free range of a bunny proof room(s). Provide them with a litter box, hay feeder, food dish, water, and a soft place to sleep. Rabbits love the freedom to run around as they please.
Puppy Pen: Place your puppy pen in a safe location, away from excess heat or drafts. Include items listed above. Rabbits also love toys, especially when they don't have as much room to run around in.
Bunny Condos: These can be made from wood, metal or even re-purposed furniture. They have multiple floors and/or sections to them. The sky's the limit!
Cages: Some people see cages as limiting your bunny, but as long as they have room to run around, and space for their essentials, then cages are a safe, and space saving option. Just be sure to give him/her time out of the cage to get some exercise and socialization!