Choosing the Right Type of Window
By Matt Solis, Senior Editor
Generally, it’s a good idea to rely on a professional recommendation when choosing a window style for your house, but it’s worthwhile to note that some window designs are inherently more efficient than others. Here’s a quick breakdown of the most common types:
Vinyl
Vinyl frames are typically the least expensive and virtually maintenance-free. They’re only available in light colors, though, because dark colors absorb too much heat from the sun and warp the frame.
Wood 
A popular choice for aesthetic reasons, wood frames are typically only a little more expensive than vinyl, but they require diligent maintenance in order to prevent rot. They’re available in many species of wood and can be stained to match any existing décor.
Fiberglass/composite
Fiberglass frames are more expensive than wood or vinyl, but they’re also more durable. They require virtually no maintenance and can be painted any color (faux wood grains are also available).
Aluminum-clad
Aluminum frames are typically the most expensive, but they’re also maintenance-free and can take almost any color. They may not be suitable for coastal environments where saltwater is a concern.
Double-hung
These are traditional units in many homes across the United States, and they’re especially common in pre-war buildings. With double-hung windows, the bottoms slide up to open the units. They can be efficient choices, but they also have the potential to allow air intrusion between the sliders.
Casement
Popular in climates where wind is an issue, casements actually seal themselves off tighter when wind blows in toward the house. They require maintenance on hinges and seals to ensure their continued stability and efficiency.
Don’t overlook the importance of proper installation. Even the most expensive window unit won’t perform effectively if it’s not installed correctly. Be wary of any contractor who relies too heavily on expanding foams or sealants to get a window to fit—these materials aren’t waterproof and can lead to problems down the road. Pre-installation waterproofing, often completed long before the windows are installed, is the best option.
When shopping for energy-efficient windows, your first guide should be the National Fenestration Rating Council (NFRC) label. The NFRC is a nonprofit organization that provides homeowners and contractors with a standardized, unbiased method for comparing different brands and types of windows. The label will tell you a window’s U-factor, solar heat gain coefficient (SHGC) and visible light transmittance:
- U-factor is a measurement of the window’s rate of non-solar heat loss or gain. The lower the U-factor, the greater a window’s insulating value.
- SHGC is the fraction of solar radiation admitted through a window or skylight. The lower a window’s SHGC, the greater its shading ability.
- Visible light transmittance is the percentage of visible light that’s transmitted through glass. The higher the number, the more light the window admits.
To find a Diamond Certified window company in your area, click on one of the links below.
Alameda County: www.diamondcertified.org/alameda-windows
Contra Costa County: www.diamondcertified.org/contra-costa-windows
Marin County: www.diamondcertified.org/marin-windows
Monterey & San Benito Counties: www.diamondcertified.org/monterey-san-benito-windows
San Francisco: www.diamondcertified.org/san-francisco-windows
San Mateo County: www.diamondcertified.org/san-mateo-windows
Santa Clara County: www.diamondcertified.org/santa-clara-windows
Santa Cruz County: www.diamondcertified.org/santa-cruz-windows
Solano County: www.diamondcertified.org/solano-windows
Sonoma County: www.diamondcertified.org/sonoma-windows
