Typically, triple-pane windows made with krypton gas filling are the most energy efficient. A window’s frame, glass, design, and installation all affect its energy efficiency. These windows, in particular, are designed highly effectively in terms of their ability to insulate.

The most energy-efficient windows are double—or triple-pane windows with low-emissivity (Low-E) coatings and gas fills between the panes. These windows reduce heat transfer, prevent drafts, and help maintain a consistent indoor temperature. But if replacing windows isn’t in your budget, pairing your existing windows with insulating window treatments can still make a noticeable difference in home comfort and monthly bills. 

ENERGY STAR®-certified windows are the most energy-efficient windows on the market. This certification means that the window meets strict efficiency guidelines set forth by the Environmental Protection Agency. While they might cost more upfront, they can save you money on your energy bills in the long run. ENERGY STAR®-certified windows lower household energy bills by an average of 12% annually.

The most popular tint percentage for home windows is 35%. Generally, most homeowners choose a visible light transmission (VLT) between 50% and 35%, where lower numbers mean less sunlight enters the home. A 35% tint blocks over half the incoming light while still allowing plenty of natural light, which can improve energy efficiency and comfort. If privacy is a primary concern, you can opt for a tint of 50% or lower to make it more difficult for people to see inside. However, keep in mind that very dark, thick tints may offer fewer energy-efficiency benefits.

Unlike cars, there are no laws regulating window tint percentages on homes, so you can choose what you think is best. It is often a good idea to hire a professional, as they can show you samples of how different tint levels will look in your specific property, helping you make the right choice.