From all the grime, road salt and, melting snow. While you’re at it clear away the clutter and give your floors a thorough cleaning. I like to set up a tray for my boots with a waterproof mat for underneath. Check your front door. Is it drafty? A space around your door can equal a 6” brick hole in your wall. If you have a drafty door, it’s best to weather-strip the door to stop drafts. If you want to replace your door and check outdoors that are energy efficient