Photo Credit: zenera
Icicles on the eaves and snow on the roof are more than just an ornament of wintertime. They can also be instructive signs that you can use to get a sense of the way your house is using energy and a way to tell whether or not there are problems that you should address to improve your energy efficiency and perhaps even to preserve your roof structure.
With the recent snow that much of the midwest and northeast US has had in the past week, now can be a good time to take a look at your roof to see how well your house is doing in terms of energy performance. An article from Home Energy Magazine gives a good set of guidelines about reading the snow on your roof to see how well your attic insulation is working.