Window Guide

Improve your view and increase
your home’s energy efficiency with new windows

In addition to letting in light and giving you a beautiful view of your surroundings, windows are a crucial component in maintaining an energy-efficient home. The type and style you choose, and whether you plan to replace only one at a time or have your entire house done at once, can have a significant impact on your heating and cooling bills. The tighter seals and more advanced construction of many modern windows prevent cold and hot air from escaping and help maintain a more comfortable, consistent indoor climate without wasting energy. New windows also breathe new life into old houses, giving your home an updated look that is both smart and attractive. Consider the following questions to help guide you to a better understanding of how windows can affect your house:

What window designs are available?
What types of opening mechanisms do windows use?
What materials can window frames be made of?
How do windows help improve energy efficiency?
What steps should you take to properly maintain windows?

Window Design, Energy Efficiency, Materials and Maintenance

Windows are designed and installed primarily to provide three things: light, ventilation and a view of the outside world. While most windows accomplish all three tasks, some do so in a more energy-efficient manner than others. Windows are generally comprised of a sill, sash, head, jamb, frame and panes. The head is the piece that runs horizontally across the top while the sill is the part that runs horizontally across the bottom. Jambs run vertically up the sides of the window. The sill, head and jambs combine to form the frame, which may be made from various materials, and the sash, in turn, frames the panes. There are a number of window designs available, including awning, casement, picture, fixed and more.

Window Designs: The first decision you’ll need to make when purchasing a window is to determine what style is most appropriate for the room where it will be installed. Some of the more commonly used types are awning, double hung, casement, gliding, picture, bay, fixed and storm. Each has different characteristics and, in many cases, opens in a different manner. Consult the chart below to learn more about some of the available options.

Designs Description and Operation Uses and Ideal Installation
Awning Horizontal window that opens outward, usually using a crank handle.
Provide ventilation even during rain
Provide ample light
Often installed above doors or other windows
Bay/Bow Series of three or more windows that juts outward from the house. The central window may be fixed while the side windows are typically double-hung or casement windows.
Provide ample light
Offer a wider viewing angle
Add style to architecture
Make rooms appear more spacious
Ideal for use when creating a breakfast nook or in a master bedroom
Casement Vertical window that opens outward and may feature locks on both the upper and lower parts. Often opened with a crank handle.
Provide ample light
Offer a large viewing area
Ideal for difficult-to-reach areas, such as over a sink or countertop
Double Hung Traditional-style window that opens by raising the lower half or lowering the upper half.
Take up little space
Ideal for installing next to patios or porches
Frames can be used to complement home décor
Fixed Available in many shapes and sizes and cannot be opened.
Used for a variety of purposes from picture windows to small, decorative windows
Do not provide ventilation
Gliding A side-by-side pair of windows that slide side-to-side rather than opening outward or upward.
Offer a contemporary look
Ideal for installation near outdoor living areas
Picture Large, fixed windows that cannot be opened.
Provide ample light
Allow for a wide viewing area
Do not provide ventilation
Storm Used in conjunction with existing windows.
Increase energy efficiency during extreme weather conditions

Energy Efficiency: Heat can pass through windows, whether it’s leaving your warm house to escape out into the cold winter air or entering your home and making it stuffy on a hot summer day. Light passes through them as well, and though it brightens rooms, it can also fade furniture and carpeting. It’s important, then, to purchase energy-efficient windows. Windows with the ENERGY STAR approval will save money on heating and cooling bills compared with units that do not have the rating. Though the ratings used to determine energy efficiency vary depending upon climate, the two most important factors are U-value and solar heat gain coefficient, or SHGC. U-value is a measure of how well a window prevents heat transfer. The lower the value, the more effective the window is at stopping heat from passing through. SHGC measures how much heat from sunlight passes through windows. As with U-value, lower values indicate higher resistance.

Double- and triple-pane windows are more efficient than single-pane windows and may reduce outside noise
Low-emissivity (or low-E) window coatings minimize the amount of UV rays that can get through glass, letting light in while reducing heat transfer and helping to prevent fading
Tinted windows and window shades help reduce fading
Make sure windows are properly sealed to prevent air from leaking through
Air leakage should be less than 0.3 cfm/ft²
In new construction, position windows so they won’t be subjected to direct sunlight during the hottest parts of the day, particularly in warm climates

Materials and Maintenance: Window frames may be made from a number of different materials, including wood, vinyl, aluminum and fiberglass. Wood can be painted and stained to match your décor. Vinyl is generally colored all the way through, meaning that there’s no need to paint it and scratches and nicks will be less evident. Both wood and vinyl are nonconductive and perform well in terms of efficiency. It’s important to keep both frames and windows clean to maintain performance and keep up appearance. Make sure your house is well ventilated to help prevent the buildup of condensation on windows.

Use glass cleaners to remove spots from windows
Avoid hitting windows with high-pressure streams of water, as they may break
Some glass coatings help prevent spots and streaks to minimize cleaning
Clean frames with cleansers that are only mildly abrasive, and make sure to test a small, inconspicuous spot first

Features

Skylights and Roof Windows: In addition to conventional windows, another way to add light and create the appearance of space in your home is with the addition of a skylight or roof window.

Stained Glass: If you want to add a unique element of beauty to your home, you may want to consider installing a stained glass window. The designs and patterns from which you can choose are virtually unlimited, allowing you to select a window that suits your décor and personal style.

Weatherstripping: Weatherstripping is essential to maintaining a high level of energy efficiency. Make sure the windows you purchase provide high-quality weatherstripping.

Screens: Having the windows open when the weather is nice is great, but chasing bugs around the house with a flyswatter is not. Screens allow you to enjoy a refreshing spring breeze without having to worry about the buzz of insects interrupting your relaxation.