Thanks for the comments opie, :thumbsup:
venting at the moment isnt a problem, i have a PC fan for intake but i dont turn it on usually because it sucks in cold air and lowers temps. In the summer i'll be doing a lot of guerilla growing (hopefully with the seeds off my Lowryders) but if i am growing up ther i'll just add another PC fan for extraction, our summers are usually mild here anyway. I hear space heaters are pretty heavy on electricity but it may be my only option if i want a good yield. I saw 40W 'warming pads'' being adverised, its like a mini electric blanket but mightnt give off enough heat. I must try and get my paws on a bit of insulation aswell.