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Are there any tax advantages? For sliding glass doors? For window film?

Yes, there are tax credits to purchasing any ENERGY STAR window or door, including window films. This includes sliding glass patio doors and French doors. There are no ENERGY STAR garage doors because this is unconditioned space, therefore these will not qualify for any sort of tax credit.

How can I find the ENERGY STAR rating for my doors and windows?

Contact the manufacturer of your doors and windows and they will be able to give you that information. It is based on your climate zone and the particular requirements. Not all doors and windows qualify in all climate zones.

How do I know if my doors and windows are ENERGY STAR qualified?

Due to the various climate zones and the differing standards for each zone, it is impossible to be able to provide a list to you. The best thing to do is to contact your window or door manufacturer and ask them directly. They know your zone, and they know the windows and doors you have and will be able to make that determination for you.

I'm going to replace my window sashes. I'd like to find some that are ENERGY STAR qualified so that I can get a tax credit.

Unfortunately, there are no sash replacement products that will suit this problem. The ENERGY STAR rating is given to a window unit as a whole, not on portions of it. A window sash does not qualify for a tax credit.

I'm replacing storm windows, but I can't find any qualified ones. Why?

When windows and doors were less energy efficient, it was very common to install storm windows and doors. However, with the great advances in technology, the new ENERGY STAR windows and doors are designed to be much more energy efficient. Most windows are manufactured with multiple panes of glass with a gas inbetween them allowing them to achieve a high level of energy efficiency. The better made frames and the Low-E coatings also make storm windows and doors unnecessary.

Currently there is no independent third party evaluator to test these products.

What are ENERGY STAR doors and windows?

ENERGY STAR doors and windows meet the very strict energy efficiency specifications established by the DOE. They have been tested and certified by the NFRC, which is the National Fenestration Rating Council; an independent third party certification agency that tests the complete window or door system and not just the glass. The qualifications are based on U-factor and the SHGC ratings for the four climate zones. Manufacturers can meet the qualifications in numerous ways including using some of the following methods:

-> multiple panes of glass
-> Low-E coatings
-> improved framing materials
-> warm-edge spacers between the panes of glass

What does ENERGY STAR qualified mean?

ENERGY STAR qualification means that the doors and windows with this designation meet or exceed the established energy efficiency standards required. This program was first established in 1992 by the US Environmental Protection Agency (EPA) to identify and recommend energy efficient products.

Products that meet these requirements have a sticker on them as a quick way for consumers to identify appropriate products that will save them money and also conserve energy. Energy Efficient does not have the same designation as ENERGY STAR, so be aware of this while you are shopping for new windows and doors.

What is a SHGC (Solar Heat Gain Coefficient)?

This value tells you how well the window blocks sunlight heat transfer. The lower the number, the higher the efficiency. The numbers range between 0 and 1, so values from 0.25 to 0.75 would be considered typical values.

What is Low-E coating?

This is a very thin coating that is invisible to the naked eye that will prevent heat transfer across the glass, keeping the heat inside the house during the winter and outside during the summer.

What is the gas used? Why?

There is gas placed in between the panes of glass in your windows because it has been proven to provide much better insulation. Either argon or krypton are used. Both are odorless, colorless inert gases that are nontoxic. They are used instead of air because of the increased energy efficiency. Argon is less expensive and more easily obtained, whereas krypton is a better insulator. Many manufacturers use a blend of air, argon, and krypton for the most ideal blend to balance both performance and cost.

What is U-Factor?

This measures heat transfer through a window to evaluate how well it insulates. The lower the number the better. That means that it resists heat flow both in and out. These factors range from 0.25 to 1.25.

What kinds of frames should I look for when I purchase a window, door, or skylight?

The frame by itself has no rating. The ENERGY STAR criteria is based on how the entire unit works as a whole. What you should look for is the rating for the overall window, door or skylight rather than just the framing material.