When you think about a garage door, you think about the large *retractable* door that you open when you drive your car in. This door needs to be weather-stripped and insulated so that air doesn’t enter or escape the garage. But most garages have a *regular* door on the side of the garage that allows people to get in and out of it without having to use the bigger door. Any of these doors also need to be weather-stripped and insulated.
Treat as an exterior door
If you have an attached garage, the door between the garage and the house should be treated as an exterior door. This means that it should be insulated and weather-stripped, usually with foam insulation.
*Retractable* garage door
If you want an insulated garage door, the only option is to buy an insulated one. Since you cannot insulate your current one, it’s a good idea to look at this option when you are first building a house or if you are replacing an old garage door. These insulated garage doors have foam insulation in them as well as an insulation covering. Though this is a more expensive option than a non-insulated garage doors, it will pay off by keeping your house more energy efficient as well as helping to protect your car from the damages that extreme temperatures can do to it.