We have a BullMastiff puppy living in a 30 foot max bach apartment, with a CRAZY chorkie.
before you all freak we are moving to a bigger place but it is still an apartment. They both do swimmingly, we only go on one small walk a day, and a drive to take dad to work. They work each other out. BullMastiffs are supposed to be a lazy bum breed. sleep all day and night if you let them. I have a friend with a BM who can barely be pressed to get up to go pee and eat! Make sure you do your research and look into exactly what you want and what will be good for that pup but don't stress yourself over what everyone else is going to think as long as you have gumption and research on your side.