Your house acts like a chimney where warm air rises and escapes in the attic through any gaps or penetrations of the homes envelope. When this happens cold air enters the lower areas of the home. A home with a leaky envelope is a home that is cold and drafty. A house with a poor and leaky envelope will show significant heat loss through the attic and eaves (as is shown on the right). When the conditions are right this will also lead to ice dams that can be very damaging to the roof.

The example below shows a significant air leak next to an attic vent. As part of our insulation and weatherization services, we spend a considerable amount of the time sealing up these leaks.