Many thanks Mikael
I didnt know it was possible to have a gateway with the two options. That is very interesting and perhaps it may be the best solution for my project.
May be for the actuators/relays I can use esp8266 as I will anyway have a lot of power available from the wall plug power supplier. Also wifi access is something I am more familiar. RF is something I have not used before.
For the temperature sensors which are located close to the actuators/relays I can still reuse the same esp8266.
For the rest of the temperature sensors I can use nRF24L01+ with batteries and this will allow me to not have cables hanging around. In general I would prefer to not use batteries so I dont need to bother replacing them periodically, however, after looking at the product you mentioned (sensebender) it seems batteries will last very long time and it looks easy to set up.