How to Buy Windows

Tips on How to Choose, Measure, Buy and Install Windows

By Mark J. Donovan

Whether you’re planning on installing windows yourself or hiring a window installation contractor to do it for you, there are a few key tips on how to buy windows that you should follow. Window types, styles and sizes are all important factors when buying windows. Moreover a window’s quality level, ease of maintenance, and energy efficiency are other important considerations.

Window Types

When buying windows it’s important to consider the type of windows you want to use. Windows are manufactured in a number of types of materials, including wood, vinyl, and aluminum.

Some of the best window types, and most expensive, are made out of wood and are coated with an exterior vinyl or aluminum sheathing. These types of windows look fantastic from the inside due to the exposed wood, and hold up extremely well to the weather elements due to the vinyl/aluminum exterior coating. They are also extremely energy efficient. All vinyl windows, on the other hand, are the least expensive and correspondingly are susceptible to expansion and contraction issues, and are not that energy efficient.

Window Energy Efficiency

When buying windows it’s also important to see how energy efficient the windows and actual window panes are. Today’s most energy efficient window panes consist of 2 layers of glass with low-E insulation material sandwiched in-between them to block out the sun’s Ultraviolet light.

Window Types

There are a plethora of window types to choose from but a couple of the most common are the double-hung and casement style windows.

Both types of window are designed to open to let in fresh air. Other window types include garden windows, bay windows and skylights, just to name a few. There are also stationary windows that do not open, such as door side light and transom windows.

Measuring Windows

Regardless if you’re planning to have someone else install the windows for you it is in your best interest to measure the window frame rough openings yourself.

This way you can confirm the window sizes the window contractor plans on ordering. Typically when buying windows it can take several weeks to receive them, so the last thing you want to have happen is have the wrong size windows show up on your doorstep.

When measuring a rough window frame opening, measure from top to bottom on both ends of the window frame and in the middle of it. Likewise do the same along the sides of the window frame opening. Finally, measure the diagonals to see if the rough window frame is square.

After measuring the rough window opening review the window buying guides from the various window manufactures and select windows that specifically call out for your size window frame rough openings. Typically the actual window frame will be approximately 2 to 3 inches shorter and narrower than your window rough openings.

How to Install a Window Ebook

You want this type of disparity between the rough window opening and replacement window to give you room to square up and plumb the window within the window frame. If the new window replacement fits too snuggly inside the window frame the window frame may end up binding on you and not operating smoothly, if at all.

If you’re buying windows directly off the shelf from a home improvement center, use your measuring tape to check the outside edges of the windows. Measure the window from top to bottom and side to side, as well as along the diagonal. Make sure the window measurements from top to bottom and side to side are approximately 2 to 3 inches less than the height and width of the rough window frame opening.

Installing Windows

When installing new windows it’s important that house sheathing be installed around the window frame opening first.

In addition, the windows should be nailed into place via the side window flange tabs that come attached to the windows. Before nailing the window to the window frame it is important to make sure the window is square and plumb. Normally shims are used in the process of squaring up and plumbing the window.

After the new windows have been installed insulation foam or fiberglass insulation should be installed around the interior window frame edges. Finally, interior and exterior window trim can be installed to complete the window installation.

For more information on Installing Replacement Windows and Interior Window Trim

  • See the Installing a New Window Ebook from  The Installing a New Window Ebook provides easy to understand, step-by-step instructions, on how to remove an old window and install a new one. Pictures are included for every key step in the process.
  • See the Installing Interior Window Trim Ebook from  The Installing Interior Window Trim Ebook provides easy to understand, step-by-step instructions, on how to install interior window trim around a window. Pictures are included for every key step in the process.

Related Information

Additional Window Installation and Maintenance Resources from

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