Window frames are an important part of a window's overall energy efficiency.
Maintenance is a critical issue. Some window frames are maintenance free, while others need annual attention. Lifestyle and tolerance for repair and restoration should determine the window frame you choose, along with energy efficiency and budget.
Fiberglass and Composite Frames
Fiberglass frames can be glass-fiber-reinforced polyester or other Fiberglass composites. Choose an insulated Fiberglass frame to achieve or surpass the thermal efficiency of wood - not all Fiberglass frames are insulated. Choose a Fiberglass frame without metal spacers and rubber gaskets. Instead, inquire about silicone foam or polymer, and butyl-wrapped materials. Because Fiberglass composite frames are new to the marketplace, it's uncertain how color choices will stand up to long-term weathering. Darker colors may fade. When purchasing, look for uniform color throughout the frame.
Fiberglass is not the only composite frame. Composites of wood particleboard, wood polymers and a mix of resins (similar to the natural resins used in plastics) are being used to make hybrid frames. Window frame technology is moving at lightening speed and composites promise many new choices in the future.
Insulated Fiberglass is highly energy efficient
Virtually maintenance free, if not painted
Will not swell, warp, or rot
Priced between vinyl and wood, but affordable
Smaller profile, fits directly to brick or stonework
A relatively new option - availability may be an issue
More expensive than vinyl
May be available only in limited colors
Can be almost as expensive as the most expensive hardwoods
Due to fragile joints, frames must be handled carefully at installation
Perhaps difficult to repair
Vinyl-Clad Wood Frames
Vinyl-clad wood frames are considered an equal insulator to wood frames.
The strongest of all residential windows
Highly energy efficient
Exterior is wood covered with a thin vinyl coating
The interior frame is natural wood
More expensive than wood - the most expensive of all the options
Wood, while undeniably the most aesthetically attractive choice, needs attention to detail, and annual maintenance will appreciably extend the life span. Rotting wood or debris in cracks should be removed with a pointed object (like a screwdriver), and then filled with epoxy putty. When purchasing new wood windows, ask the manufacturer or vendor if you can expect tight-fitting joints, unblemished surfaces and invisible finger joints. If the answer is yes, check them when they are delivered and reject all that do not meet your standards.
Highly energy efficient if properly treated for the life of the window
Durable and strong
Readily available and easily customized
Any color or stain is possible
Most hardwoods can be used
Still considered the gold-standard - the classic window
Expensive, but not as expensive as vinyl-clad wood
High maintenance - annual maintenance required for long-life
Stain or paint required every 3 to 5 years
Lower life expectancy due to wear from sun, wind and moisture
If not properly protected from moisture, can swell, rot, warp and stick
Vinyl PVC means poly-vinyl chloride. Shop for vinyl windows that are manufactured with a thermal break. The thermal break is usually an internal metal network that strengthens the window, as well as improving its energy efficiency. Look for joints that are heat-welded rather than joined with screws or other fasteners, and a uniform color throughout the frame.
Lower cost than wood or aluminum
Low maintenance - never needs painting
Impervious to the elements
Frames can be built to fit any size opening
Many frame styles to choose from
Can be cleaned with a natural bristle brush
Superior insulation - an interior honeycomb structure boosts insulation capability
Vinyl window sales are growing rapidly due to energy efficient performance
Not very rigid - needs internal hollow chambers; the more chambers the better
Thermally improved frames are the best of aluminum frames. A "thermally-improved" frame decreases heat loss and improves energy efficiency by the addition of a non-conductive material between the aluminums on the interior and exterior of the window. This addition is known as a "thermal break." Thermally improved aluminum frames are superior to standard aluminum frames.
Aluminum framed windows should be considered only with a thermal break. The thermal break in aluminum windows is usually a strip of rubber or plastic, placed between the inner and outer frame. The thermal break lowers the ability of air to pass through the aluminum. Without the thermal break, the window will not be energy efficient.
Light-weight, durable and strong
Do not absorb water
Do not rust or rot
Resistant to warping and sticking
Fits directly to brick or stonework
Works well in warmer climates
Can be cleaned with a natural bristle brush
Less expensive than wood or composites but more expensive than vinyl
Considered the most secure of all window frames
Lose heat easily, reducing the energy efficiency of the entire window