Rabbitats are partly in ground or insulated to keep the bunnies cool in the summer and warm in the winter. They are also placed within a fenced and locked perimeter to keep animal (and human) predators out. The bottom underneath the hutches and their running area are also provided with buried wire fencing, to prevent predators from coming through the ground.
The hutches can be build like a box with many compartments and holes for the bunnies to go in and out as they please. the top or one side must be on hinges, to allow periodic cleaning and emergency access (e.g. for a sick bunny) If a back support is added, the hutch can be a bench to sit on when visiting the bunnies. Or a hot bed for plants can be built on top. The choice of plants must be compatible with rabbit diet, and a screen protects them from being eaten to the root. Thus rabbits can graze on the part of the plants that grow through the protective screen, and the plants can continue to grow all season.
Here are a couple of hutch design ideas borrowed from rabbitats.org:
