You can do this now by using Mike Maxwell’s zone manager. This allows you to create a virtual device which represents zone and then assign multiple sensors to it. He created it for exactly this reason, to reduce the number of false alarms by requiring multiple sensors to trigger and alert.
If you haven’t used custom code in smart things before, here’s the FAQ for that. It’s pretty straightforward, you’re basically going to copy someone else’s code and paste it into your own account.
If after reading that, you think it’s something you’d like to try, you can find Mike’s zone manager code by checking under “sensors” in the quick browse lists for smartapps in the community – created wiki.
This allows you to create a virtual device which represents zone and then assign multiple sensors to it. He created it for exactly this reason, to reduce the number of false alarms by requiring multiple sensors to trigger and alert.