The RWAF recommends a minimum hutch size of 6' x 2' x 2', which allows rabbits some room to move, stand on their hind legs and enough space for the food, toilet and sleeping areas to be kept apart. It is commonly accepted that a rabbit should have space for 3 hops, but it is commonly underestimated just how far 3 hops is - our tests show that 3 hops from an average sized rabbit covers 6-7 feet!
A hutch should only be a shelter and not the only living space. It should be attached to a secure run of at least 8' x 4'.