Seal Leaks around Doors and Windows
Add or replace worn weather-stripping around doors and windows. Caulk gaps where necessary. Replace worn door stops at the bottom of doors. If you have them, install storm doors and window. Replace old windows with energy efficient windows.
Seal Other Leaks
Use caulking and weather-stripping around entry points for all pipes and ducts that travel through an exterior wall. Install insulating kits behind electrical plugs that are on a wall with an exterior side.
Is the Insulation Adequate?
Ask the staff at your local home improvement center how much insulation is recommended in your area and then check your attic insulation to make sure it's adequate. Some homes benefit from additional wall insulation. Home improvement center staff will explain types of insulation that can be added to existing walls.
Heating System Checks
Have a heating professional do a routine-check before cold weather arrives vacuum the vents and other heating components. If it has one, replace the furnace filter. Make future replacements as needed or directed by your furnace manufacturer. Consider installing a setback thermostat. It regulates the temperature, allowing the home to be cooler when you are away or asleep. Fill oil or propane tanks.
Check the Fireplace
Have the chimney inspected and cleaned. Close the fireplace damper when not in use. Read more about wood burning and gas log fireplaces.
Check the Roof & Its Neighbors
Replace loose shingles. Make sure the flashing around the chimney or vent pipes is watertight. Check the bricks and mortar. Install a screen at the top of the chimney to keep leaves and other items out. Clean drain gutters and point downspouts away from the house. Trim tree limbs that are hanging over or touching the roof.
Winterize the Plumbing
Take care of known issues with pipes that freeze. Heat tape can be used to keep them warm during extremely cold weather. Learn how to turn off water at its source so that you can stop leaks immediately if they start. Drain water from outdoor faucets when you think a hard freeze is coming.
Winterizing Outdoor Items
Give decks an additional coat of sealer. Check the foundation and siding for cracks or gaps. Repair as necessary. Drain garden hoses, roll them up, and store them inside. Close and cover the swimming pool. Prune shrubbery and add mulch to perennial flower beds. Cover outdoor furniture or store it inside.
Collect Emergency Supplies
Candles and matches or a small butane lighter. Flashlight and batteries. Fill propane tank or buy charcoal for outdoor grills. Battery operated radio or weather radio. Buy extra batteries. Snow blower, shovels, and/or chemicals to melt snow. Containers of bottled water. Non perishable food to last a few days. Be sure you have a hand operated can opener. Paper plates and plastic eating utensils. Paper towels. Extra firewood. Fuel for your generator. Kerosene and kerosene heater (use with carbon monoxide monitoring strips)
That's a start! There may be additional winterizing duties that are important for your area. If you're new to town, ask your neighbors how they prepare for winter.
