I live in a basement flat with my sister Lilly and our good friend Will. We all have dogs of our own at home with our families and Will is even a wildlife photographer (so if you have a more exotic pet..). The flat has hardwood floors in the main areas and carpeted bedrooms. The flat is open plan so there is little chance of doggy confusion. We also have an outside area with wooden decking, furniture and a few plants. The decking acts as a drainage system and I have absolutely no problem letting your pal use it whenever needed (need I say more). Again, we live in a basement flat and therefore the outside area is below street level with absolutely no way of an escape, even a cat would have a mission on their paws. I would feel completely confident in leaving the door open during the day in the summer if your dog is used to coming in and out as they please. We also allow dogs on the furniture but happy to ask them not to if that's what they're used to!