Energy Efficiency and the Building Envelope
If you know anything about energy efficient homes, you know that the tighter the seal on windows and doors, the more efficient things will be. Of course it helps if you have efficient appliances, heating and cooling systems that use as little energy as possible, and you do the little things like turn down the thermostat before you go to sleep and when you leave the house. But no matter how efficient things are, if your building envelope isn't sealed up tight you'll be fighting a losing battle.
Heating the Great Outdoors
The building envelope is the outer layer of your heating and cooling systems. Think of it like the seal that keeps heated air inside and cool air outside during the winter, and the opposite during summer. If you're running your heat during the winter and you have a leak in your building envelope, you're heating the great outdoors and losing a lot of your heater's efficiency in the process.
Sealing the Cracks
Checking to ensure that your building envelope doesn't have leaks will increase the energy efficiency of your home during every season. During the wetter months, you may develop weak points around windows or doors that then allow drafts and reduce the effectiveness of your temperature control systems in the house. If you know what to look for and where to look, you can ensure that your home is as efficient as possible. You can also add drapes, use door pillows at the base of doors, and attempt to reduce drafts in less permanent ways.
If you're not sure what you can do to improve the efficiency of your building envelope, consider contacting an experienced contractor. A quick visit and a few fixes will be well worth the energy savings you get once your building envelope is sealed completely.