A -- When it comes to overall energy efficiency and street appearance of a house, people often forget about the door on the garage. Keep in mind that on a typical home, the garage door covers more than 30 percent of the frontal area. With lifetime warranties on many of the models, a new efficient, insulated garage door can be a good investment in your home.
Even though an attached garage is not heated or cooled, its energy efficiency still has an effect on your monthly utility bills. Just think how many times each day the door from the house to the garage is opened. Each time, it lets a gust of cold or hot, humid air enter your house.
The two primary design features that impact the energy efficiency of a garage door are the thickness and type of insulation and the airtightness of horizontal weather seals between each of the panels. The number and quality of the glass, if you select a door with windows, is also important if you plan to work in the garage. For most activities in the garage, the natural light from a series of windows is adequate without having to switch on an electric light.
Since the panels constitute the majority of a garage door, their insulation level has the greatest impact on efficiency. Insulation levels in top-quality, 2-inch-thick doors range from about R-6 to R-18. Choose a door with a plastic thermal break between the indoor and outdoor steel skins. This blocks a direct path through the metal for heat to bypass the insulation.
Injected polyurethane foam provides the highest insulation value in the limited space between the garage door skins. The other effective insulation type is a piece of polystyrene foam (like a cooler) that is placed inside the door before the two skins are sealed together.
Check the joint design between the door panels for safety and efficiency. The newest designs are pinch-resistant joints that tend to push fingers out of the joint as the door closes (great around children). With the complexity of the mating surfaces, pinch-resistant joints also tend to be very airtight.
Several of the best standard seal designs to look for are tongue-and-groove, shiplap, compression, and flexible polyurethane. Tongue-and-groove and shiplap joints form an interlocking seal between the two panels for lifelong seals. There is no flexing or compressions as with the other two designs. Some garage doors use a combination of seal designs.
Although the garage door opener has an impact on the noise level when a garage door opens, the design of the door is most significant. High-quality rollers, hardware, counterbalance springs, and adjustable tracks reduce the noise so that it will not wake you, even with a bedroom above. For do-it-yourself garage door insulation, consider a garage door with a safe counterbalance spring adjustor.
The newest garage doors are carriage-styles. When closed, they resemble side-hinged carriage doors. They open upward though, like a regular section garage door. Some use insulated steel with wood trim while others use all real wood with insulation. Grained, stainable steel doors also resemble real wood. Beautiful copper (resists salt air) and tough composite plastic door skins are also available.
Another recent improvement is the use of energy-efficient windows in the garage door for natural light and decorative qualities. You can choose durable crystal-clear acrylic plastic windows in attractive beveled and leaded designs.

Write for Utility Bills Update No. 894 for a buyer's guide to insulated garage doors. Include $3.00, a business-size SASE, and Update number. Mail requests and questions to James Dulley, Kentucky Living, 6906 Royal Green Drive, Cincinnati, OH 45244. Go to www.dulley.com to instantly download.