I’m on the train through Surrey on my way into London and there is still a thick blanket of snow on the ground. But not necessarily on the roofs: some are covered and some are bare. Occasionally the rows of terraced houses alternate like squares on a chess board. And it all depends on heat loss.
It’s funny catching such a stark glimpse of something that is ordinarily invisible. Heat, and therefore money, from these homes is gushing out through the roof. Ordinarily the symptoms only appear on a monthly bill where they’re too abstract and unlikely to have any effect at all. What do you suppose would happen if people could see a bit further up the red end of the spectrum and looked at their own houses on a chilly morning?
carbon limited 
Its been a while, mate. Did you ever see this?
http://www.seeit.co.uk/haringey/Map2.cfm
Its Haringey doing Thermal mapping of the borough. They said it was to highlight properties with poor insulation. Others said it was to catch people growing weed in their loft!
I have been pleasantly surprised at the amount of houses round here that still have loads of snow on the roofs, though several have gaps where the eaves are
I posted about that in 2007. http://carbonlimited.org/2007/05/07/spy-plane-photos-shame-heat-loss-homes/. Funny you mention the pot, because that’s just what Bealers said at the time.
Hmmm… I seem to have left 4 comments on that post. Must be EOA