is it of high electric consumption? well, you buy a kit based on how many Watts it consumes according to the room size. what you don't know is how often it will be on consuming that amount.

i will be fitting it in my bathroom. i know that i should have a qualified electrician wire it in, but i want to do all the prep work in advance. where would it be wired in to, as obviously you don't have a ring main in the bathroom? just tap in to the one in the room next door i presume (the upstairs circuit)?