Large windows without bars as well, but then burning to death in a fire isn't too appealing either. Ruins the view too. Maybe the right answer is to kill intruders as they present themselves at the border.

I know people that have these glass doors they don't even put up curtains. You can watch them all night if you're a peepin tom. People have a false sense of security these days

Wouldn't an out of sight rear window be better for gaining access? I know because I saw it on a TV show once.