Mastiff considers himself a part of your family and he feels the most comfortable being with his beloved owners. Many mastiff breeders care for their puppies and give them only under condition they will live in a house.
Mastiff needs an own place at home. As any dog, he needs one to feel safe and comfortable. Dog cage is also a good decision, especially for a puppy. The best one is a wire dog cage. It is difficult to break or chew. Get the largest one you may afford to let a dog grow in it.
Dog bed by the side of yours will do also. Mastiffs love being near their owners. But do not allow a dog to your bed, as a dog will be at the same level with you and thus the problem of dominance may arise. Besides, jumping from a bed or coach is harmful for the joints of a young dog.
Many mastiff dogs like sleeping on hard surface because it is cooler. Pay attention to it: mastiffs like to flop on the floor with all the fluff.
The best bed for mastiff is a baby mattress. Do not surprise if your mastiff tears his bed to pieces. It is his favorite entertainment. Just clean the pieces before your puppy swallows them.