Daily access to unfiltered natural sunlight i.e. not through glass, especially in the juvenile growth phase, is vital for vitamin D3 synthesis and correct development of the teeth and jaw bones. Your rabbits accommodation should be sheltered from the elements, secure from predators and as spacious as you can possibly make it. The absolute minimum dimensions for a rabbits accommodation is three times the length of the rabbit housed when stretched out at rest and it must have enough vertical height to allow it to sit up fully on its hind legs. A secure outdoor run should also be provided, ideally attached to the main housing allowing it unlimited access to the outside. It is important too that house rabbits have access to the outside.
Things to include in a rabbit friendly run to encourage natural behaviour:
If you keep your rabbit inside they will chew anything at their level. Make sure any hazardous house plants and electrical cables are covered or out of reach.
Current research suggests that it is beneficial to provide UVB lighting, such as that routinely used in birds and reptiles, when rabbits lack access to unfiltered sunlight. Recommendations are that the lights should be placed within 9 inches of the rabbits cage and the bulbs changed every 6 months, as the quality of UVB radiation produced decreases over time.