Air penetration is another important element to consider. Care is taken during construction and before the insulation phase to block up all the holes that would let outside air into your home. Most new homes today are a lot tighter then the older homes of the past, but they still leak quite a bit of air. This air leakage is like having a window open all the time in your new home. This, as you can see, can cause heat bills to skyrocket. The newer technique builders are now using is to make your home real tight and then control the fresh air that comes in. The controlled air is brought in with a high tech mechanical means. You will find that the home stays a more constant temperature at all times, with less air leakage.