Having a garage door with proper insulation definitively cuts down on total household energy usage as long as the garage is actually attached to the house itself with a shared wall or roof, or if the garage is used as a living or working space.
In fact, garage doors have such an impact on energy consumption in such homes that the IRS has officially labeled certain models as being subject to an 'energy savings' tax credit. Because of the energy tax incentives act of 2006, anyone planning to install a garage door that meets the criteria is eligible to receive up to 500$ from the federal government.
Homeowners wishing to take advantage of this benefit should get in touch with their garage door installation dealers in order to get certification from the manufacturer that the door meets the criteria.
The best, most reliably efficient insulated garage doors feature three layers- one of CFC-free, environmentally-safe polystyrene, which is bonded to the two outer layers of sturdy, rust-resistant steel. This is not, however, the only type of door that will be eligible for the tax credit.
The three-layer model also cuts down on the noise a garage door opener will produce in opening it, and will be more highly resistant to the nicks and dings pf daily life. These doors have exceptional lifespan.