A Buyer’s Guide to Windows
They’re one of the most important—and expensive—parts of a house. We help you sort through the materials, styles, and ratings that will influence your choice.
Magazine extra: Check out our guide to window aesthetics, where you’ll learn which styles work best where, and why. We’ve also included a source list of national and smaller specialty manufacturers.
When you roll up to a house for the first time, you can’t help but notice the windows. Their size, style, and placement determine if they’re appropriate to the architectural style and, to some degree, if the house will be a pleasure to be in.
For most people, that’s as much thought as they give to windows. And that’s too bad, because picking the right windows can lower heating and/or cooling costs, improve comfort inside the house, and improve indoor-air quality by dramatically limiting condensation.
To buy the best-performing windows for your house, though, you need to know a bit about how they work and what they need to do.
A window has four basic jobs
The first thing a window has to do is control heat gain and loss. Technically, these temperature changes take place through conduction, convection, and radiation. As a practical matter, these temperature changes affect your comfort. If you’re sitting next to a window, you’ll experience conduction and convection when the glass acts as a cold radiator in the winter; and you’ll experience radiation on a sunny day when you feel like an ant trapped under a magnifying glass.
Second, a window must control solar-heat gain. I say control because heat gain isn’t always bad. If you live in a heating climate — generally speaking, anything north of Oklahoma with the exception of California — you should take advantage of the free heat windows can provide.
Third, windows need to regulate airflow. They should be airtight when closed and also offer fresh air when you want…