Best Window Frame Materials & Styles

Window Frame Materials

Wood Window Frames

It is a well-established fact that wood frame windows are excellent insulators. However, they do come with several notable pitfalls. Wood frames tend to expand and contract according to various weather conditions. They can also be rather heavy and thicker than other frames. This will make storage more difficult, along with reducing the amount of natural light able to flow into your home. Wooden frames also require the highest maintenance, while aluminum or vinyl clad wood frames typically reduce the need for constant maintenance.

Aluminum or Metal Window Frames

Although strong, durable, and nearly maintenance free, metal or aluminum window frames conduct heat very rapidly. Due to this, metal window frames make for a poor insulating material. To reduce heat flow and the U-factor (The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating properties), metal frames need a thermal break, which is an insulating plastic strip placed between the inside and outside of the frame and sash.

Fiberglass Window Frames

Fiberglass window frames offer both dimensional stability, and air cavities. When these air cavities are filled with insulation, they offer superior thermal performance when compared to wood or vinyl frames. This acts in a similar way to insulated vinyl frames.

Composite Window Frames

Composite window frames consist of composite wood products, such as particle board or laminated strand lumber. Not only are composites extremely stable, but they offer the same, if not better, structural and thermal properties of conventional wooden frames. As an added bonus, composite frames provide increased moisture and decay resistance.

Vinyl Window Frames

Vinyl window frames are generally composed of polyvinyl chloride, better known as PVC. This particular type of PVC has been infused with UV light stabilizers which helps protect the frame from being harshly affected by sunlight. PVC is one of the most versatile plastics, providing a good insulating value, good moisture resistance, and no need for painting. On the other hand, at high temperatures PVC is prone to warping, and at extremely low temperatures the frame is prone to cracking. Colors other than white are also prone to fading if exposed to direct sunlight for several hours a day for a prolonged period. Insulated vinyl frames are also available. Insulated vinyl has cavities filled with insulation, making them superior to standard vinyl or wooden frames. These high-performance frames are used in conjunction with high-performance glazing.

Window Styles


Awning Window

An awning window is a casement window that is hung horizontally, hinged on top, so that it swings outward like a canopy.

Bow Bay Window

A multi-panel window, with at least three panels set at different angles to create a protrusion from the wall line.

Casement Window

A casement window (or casement) is a window that is attached to its frame by one or more hinges. Casement windows are hinged at the side.

Double Hung Window

Two moving sashes that overlap slightly and slide up and down inside the frame.

Hopper Window

A hopper window is a bottom hung casement window that opens similar to a draw bridge typically opening to the outside.

Picture Window

A very large fixed window in a wall, typically without glazing bars or glazed with only perfunctory glazing bars near the edge of the window. Picture windows are intended to provide an unimpeded view, as if framing a picture.

Single Hung Window

One sash is movable (usually the bottom one) and the other fixed.

Sliding Window

Has two or more sashes that overlap slightly but slide horizontally within the frame.