In the band 868 – 870 MHz, the maximum power is −27 dBW (2 mW) e.i.r.p. and the maximum permitted duty cycle is 1%, except in the band 869.20 – 869.25 MHz, where the maximum power is −20 dBW (10 mW) e.i.r.p. and the maximum permitted duty cycle is 0.1%.
That happens to match the European Z-Wave, 868 MHz and 1% duty cycle, which would mean that it's possible to use European Z-Wave gear in NZ even if the official frequency allocated for it is the weirdo 921 MHz. I'll email the RSM folks tomorrow to check, just wondering if anyone here knows more about this...