But taller than railings so that nothing could go wrong... good 'luck'... :)

I recommend they put locks on the doors to access this space and an alarm system that goes off if the doors are open. Wait till kids are in bed to enjoy some quiet time as adults on the deck. Having kids makes us do all kinds of things we would never think about or want to give up, but that's the way it goes. Safety first. That's my mommy spin. Good luck.