Insulate, of course is the common answer, but is it the smart answer in all instances? Gliderol Garage Doors' market leading continuous curtain steel roller garage door is a great argument to suggest an alternative way. The majority of garages are unheated and fitting an insulated door makes no difference to that fact! With no energy to be saved, a single skin door provides the best option.
It still brings vertical travel for park right-up-convenience, inside and out - perfect for short driveways and fits behind the reveal giving extra drive through width - ideal for today's wider vehicle and narrow garages.
In fact, a single skin solution brings everything - effective weather closure, robust security, durability, ease of automation - except the price premium of one expensive element - insulation!