Rabbit hutch designs vary, but need to provide several basic elements for the rabbit: shelter from wind and rain, a hiding place from potential predators, light, air and room to exercise. They can be made from various materials, but sturdy plywood in a solid wood frame is preferred, with wire mesh insets for light and ventilation.
Shelter from the Elements
As your rabbit will spend some time outside in warm weather the rabbit cage must have a waterproof roof. A hinged roof in two parts will allow easy access to your rabbit, and facilitate cleaning.
A Secure Hiding Place
Rabbits are prey animals and fear large animals that can hunt them. Provide an enclosed space 12 by 24 inches at one end of the hutch. It should have its own exterior door and an opening into the larger portion of the hutch. Ensure this space is dark, so the rabbit can sleep. The rabbit will use this space for nesting, so give it a solid waterproof floor.
Light and Air
Fine wire mesh attached over circular or rectangular holes in the plywood walls will provide adequate ventilation and light. Make the vents on opposite sides almost the entire wall size, while at the far end the vent should come down only half the wall height from the roof.
Rabbits need room to run, jump and play. Make the exercise space 6 feet long by 3 feet wide, and 3 feet high, several times the size of the mature bunny. Provide a smooth solid floor, as wire will cut the rabbit's feet. An outdoor cage can have its exercise space rest directly on the grass. Add an interior ramp and a ledge 10 inches wide to give the rabbit different levels to run on.
Hang up a water bottle inside the hutch and refresh the water daily. Use a stainless steel bowl for food pellets. The rabbit will chew a plastic one and can get sick. Ensure adequate room for these items in the rabbit cage.
Indoor Rabbit Cages
Indoor rabbit cages can be smaller, four feet long in total and mounted on lockable wheels for easy movement around the house. Construct them like the outdoor hutch but with a solid floor throughout. Indoor rabbits will exercise outside their cage, while being sociable with children and adults. Rabbits can be litter-box trained easily indoors. Keep the litter box in the exercise area of their hutch and empty it a few times a week.
In both an outdoor and indoor rabbit cage, provide lots of non-toxic wood, bamboo, and rattan items for your bunny rabbit to chew on, so it will not be tempted to chew on its cage. Should it start chewing on the cage walls, doors or floor, remove those materials immediately and replace. Once it is mature, supplement its food pellets with chewables like carrots, cauliflower and broccoli.
You can effectively meet your rabbit's need for shelter, security from predators, access to food and water, and exercise space in a moderately-sized shelter, which you can affordably build yourself.