And its probably in for the winter now.
How about insulating the shed for the winter?
http://www.carcoon.c...ces-europe.html
Yes to the carcoon, no to insulating the shed.
I insulated my shed with polystyrene boards then ply over the top. I get a bit of condensation with it now so wouldn't recomend it. I have solved it with those little CaCl2 moisture traps but for the amount of heat it saves its not worth the effort.