Hey Jim,
That's AWESOME. LOL, I know it sounds crazy, but this article is 100% on the money. My wife and I, unfortunately, do not have a terrace...but we would really like one. One of the major items of concern would be 'kittycide.' Personally, I am not a fan of cats being outdoors in the suburbs either (they wipe out a lot of the birds, etc) without some sort of limit.
James