Adequate lighting. A proper footing, and a durable floor. At least two ways in and out. Walls and a roof appropriate to the climate, given when it will be occupied, if not the usual seasonal extremes in it’s setting. Access to drinkable water. A bed, perhaps a chair, and if possible a desk of some sort. Ideally, a stove, oven, or at least some method of cooking. As long as were talking the Palace of Versailles, maybe a pantry cupboard, ice box or fridge. Somewhere to set down a drink, book, or stray objects. Curtains might be nice, though mosquito netting where and when that’s appropriate is worth having. An outdoors to go to, and someplace in between, where you might leave or clean your footwear as necessary, or go for a smoke or perhaps for fresh air. A well-engineered toilet. As a bonus, some contraption set up about showering or bathing. At least some proximity to a store, or room enough nearby to lay in provisions between supply runs. Another pair of shoes, stationery, a map of the surroundings, and at least an idea of a good route for walks. Points to consider anyway.