When it comes to keeping our homes at a nice, comfortable temperature, most of us understand how important it is to have good insulation in our walls. But what we may not realize is just how much heating and cooling we can lose through our doors—especially our garage doors. Many of us use our garages as a main entrance to our homes. Whether we’re coming home from work, from school or from running errands, if we’re using our cars, typically the garage is the way we get into and out of our homes. That means that to keep our homes really comfortable, we need to make sure our garage doors are adequately insulated. And that’s where R value comes in.