To weatherize a home means to prepare it to withstand temperature changes and extreme conditions from outside. Weatherizing a home can save tons of energy and tons of money on gas and electric bills. According to the U.S. Department of Energy, drafts alone can waste 5% to 30% of your energy use.
Caulk, weatherstrip and install storm windows to keep out drafts of cold air in the winter.
You can also use recycled materials from around the house like newspapers and old tee shirts to fit into the nooks and crannies that let air in or out.
Install screens. This way, windows can be left open in the summer without fear of bug invasion.
Take any air conditioners out of the window during the winter to prevent heat from escaping through unsealed space.
Window shades keep sun out during the day and heat in at night. Keep shades open during winter days and closed on summer days or winter nights.
Put your sewing (or hot-glueing) skills to work to make a long, tube shaped pillow out of old tee shirts and towels that can be placed at the bottom crack of a door during the winter.
Propping a door open during the summer let's in excellent cool breezes. Maybe get a screen to keep air moving and critters out.
Throw old styrofoam in your attic. Just a little can make a big difference in stopping heat from escaping your house. Spread old coolers and packing materials around your attic and let them insulate.
Other tips and tricks
Run your ceiling fan in reverse during the winter. Most fans come with a switch to reverse the way the blade spin. Running your fan in reverse when it's cold pushes warm air near the ceiling (remember, heat rises) down to where you are.
Turn down the temperature on your water heater. Most are automatically set to 140 degrees F, which is hotter than you will likely ever need. Turn the temperature 20 degrees (or more) and save your water heater some work and yourself 10% on heating costs.
In the winter, lower your thermostat a couple of degrees when you leave the house or go to sleep. And don't forget to lower so much that it won't turn on by accident during the summer.
If it's really hot outside, try taking a cool shower to save on hot water use.
Be careful of where you put light sources. Put them in the places where you particularly need them, like your desk, over a counter, and near your favorite reading spot. This way, you can have one light on at a time while you do specific tasks around the house instead of having four lights on trying to keep the whole room bright.
Wear those ugly Christmas sweaters. Grandma's gift will keep the energy use down. Just make sure no one else is home to see your style choice...