did you saw how small it is? What is capable of:

1. every node is a repeater
2. low power
3. encryption
   If you have z-wave device then you know.
   You can buy the chip but if you want to program it with sigma design sdk you must to buy development kit. You can't sell the product if you don't pass the certification .

Hi I'm new on the forum and I'm wondering if some one try to build a z-wave sensors. I have found chip that that is capable to communicate throught z-wave. Maybe it's expensive but i think from specyfication it's worth it. Here is the link to the chip
http://www.digikey.com/product-detail/en/sigma-designs-inc/ZM5202AE-CME3R/703-1071-1-ND/4135428
It's 868MHz EU Frequency