I'm really unimaginative and can't picture what kind of hardware we are talking about? What kind of controllers/processors, what type of periphery etc.
Atmel AVR micros for the nodes and an ARM SBC to run Linux on as the border router for the controllers
As far as the peripherals are concerned temp sensors/light sensor/humidity sensor for monitoring.
For control mostly our own hardware Relay or PWM output to control/dim ballasts or LED fixtures etc
