Constructing New Balcony for Cats from Scratch - suggestions to ensure it is both safe and aestheti

We are exploring the possibility of hiring a builder to create a second story balcony off of our main bedroom from scratch.  We want it to be cat proof and, ideally, still "nice" looking. We figure we'll have glass panels so there's no way to fit between any slats, but as I understand it, cats can jump as high as 8 feet.  That's quite a bit higher than I would want the sides to be ideally.  is there a way to make sure they cant jump over the top.  I can also see my nimble cats trying to  see if they can balance on the top, which would be scary... Given that we have the freedom and flexibility of building from scratch, any design ideas would be very appreciated!

I've been pondering what to do with my balcony for a couple of years now. We have child proof fly screens on our windows which are just a little bit more course than the usual ones but they are still practically invisible. 

The problem with a fence on a balcony is that you need to angle the top of the fence toward you so that the cat is deterred from jumping. The angle is quiet large, it would look ugly on a balcony.

This netting is almost invisible. You can get it in Australia and England so I expect you can get it in North America as well. 

I think it was LTS3  who shared some pics of attractive looking cage type cat balconies for the outside of windows some time ago. The are not available where I live, unfortunately but I would love to have something like that on some of mine.