How many boards I need ?

Hi,

My project is to control my home using voice recognition, for that I will use one Arduino with Voice Shield, this main Arduino it will connect using Wifi and than send commands to all the rooms. This commands will controls the lights for example.

My question is, Will I need one board for each room ? If Yes, which are the cheaper way ? Xbee / Wifi / Bluethooth / other ?

Tks

Brunno

Please post less information…especially about your house and your capabilities.