Best Small Z-Wave Door/Window Sensor

[desertblade (Ben W)]

I did. Some zwave sensors have contact points that you can purchase external contacts that you can chain together.

Here is a good post about it:

Best way to add sensors to lots of windows?

My sunroom has about 15 windows. I was wondering what the best way to add sensors to them. I was thinking 1 arduino with 15 sensors. But would that work ok in ST? $20/sensor is a little steep to use the real sensors on each one. I was also thinking, if the magnets are powerful enough, I may be able to use one sensor for 2 windows.