A 10ft x 10ft 'garden building', properly insulated with a radiator and a dimable ceiling light. There would be 2 double glazing windows opening so that when it rained the rain would run off them rather than blowing in. They'd have pretty curtains. The floor would be bare in summer, just wood, and in winter I'd have down large turtle mats. The walls would be painted a light colour, maybe pale blue, with a cute bunny border. I'd have a 5ft double hutch with legs tall enough for the buns to run underneath, a comfy but easy to clean chair and a quality wooden storage chest. None of them would be fitted so I could move them around each week. The door would have a hook on the back for coats, and a weld mesh gate that could slide across, so the rabbits could have the door open without goig on the grass. The avairy would be 10ft x 6ft (all there's room for I'm afraid) with a door that locks from the inside as well as the outside. It'd be just grass, but with a small path of slabs leading from the aviary door to the shed door.
But yeah, I've hardly thought about it really...