Did you ever notice in the winter that some homes have a lot of icicles, while other similar homes do not? In some parts of the country this is a significant problem and results in reoccurring gutter replacement as well as water intrusion issues. Most people, if you ask them, will say the cause is that the gutters are clogged with debris. While that can be a contributing factor, the primary reason is heat loss from the home. This also contributes to high energy bills and lack of comfort in the home throughout the heating season. The following is a good description of how it occurs from the Insurance Institute for Business and Home Safety.