Is half of a duplex a worthwhile purchase?

[John Park]

Of course I would like to buy a whole duplex, but the more common listing I have been finding is 1/2 of a duplex. I want to buy and hold, and I was wondering if there was anyone that could share their experiences either way. What happens when the roof needs to be done or other items that are common to both sides of the building? I guess the nightmare scenario would be an uncooperative owner on the other side, but are there any laws regarding the necessity of both owners sharing the expenses?