Most garage door systems can be repaired without replacing the door because most common issues happen with the door's systems (opening mechanisms, rails, etc.) and not the door itself. Total replacement of a door is usually only necessary when significant damage or impact has occurred to the door (usually from vehicles, but potentially from other sources). Accidentally backing into a closed garage door happens to most people's garages at least once in their lifetime, but even then, many garage doors can be fixed by replacing some panels in the affected area.