If you live in a town and have a flat rooftop this can make a great spot to keep your bees. They can fly in and out of the hive undisturbed and will have a great view.
You should check that your roof will be strong enough to support the Beehaus which can weigh as much as 136kg (300lb) in the summer when it has lots of bees in the brood box and lots of honey in the supers.