Personally, and I don't care where you live, city or country.

There are too many risks on leaving a dog outdoors fenced or chained up while you are not there to supervise, specially for long periods of time.

They could escape, hang themselves, hurt themselves, people could posion them, steal them for labs or breeding/selling, or use them for target practice... if you will.

Letting them free roam indoors, or even confined to one room is the best option in my mind, hoping that your pups can be trusted indoors with out destroying the place.

Even then you can crate them while you are away, and get a neighbor/friend, or higher a pet sitter to come out and take care of them for a while each day, so they can still get their excersize and attention.
I am a former pet sitter and I can say that it really can work wonders for the dog, and their owners.