The idea here to seal all the little cracks and holes that let cold air in or hot out of your home when you are trying to control the temperature for comfort. Even the smallest gaps can make a big difference—especially in older homes that have had more time to relax a little on their foundations. The cure can be quite simple: plug the gaps! There are a variety of tools at your disposal, depending on the size, shape, and location or the gap.
Tips & Tricks
Make it last. Choose weatherstripping that will withstand friction, weather, and temperature changes associated with its location.
Get the right tool for the job. Door sweeps can cover the gap below a door. Foam strips can fill space below or above a window. Caulking can fill odd-shaped gaps or spaces around joints.
Test for leaks. There are a couple options: 1) hire a technician to do an energy audit of your house (perhaps a blower door test); or 2) the more economical option, look around your house for potential leaky spots. To do a thorough test, turn off any furnace or air conditioning, close all doors and windows, and then tour the house with an incense stick. Pass the smoke near suspicious areas (seams, cracks, electrical outlets, etc.) and watch to see if it is sucked away. Then target your efforts towards those spots that your test reveals.
Web & Print Resources
Weather-stripping and caulking overview:
You can find leaks in a building by watching smoke or colored gas near seams—if it gets sucked into the seam, there must be a hole.