Energy Efficient Windows, Part II: Cost, Types and Frames

Energy-efficient windows are available in several configurations. Ideally, select a product that matches the architectural style of your property while also providing effective insulation. There are now windows that reduce heat transfer by more than 80% compared to conventional single-pane glass. This saves on both air conditioning and space heating, as heat transfer is reduced in both directions.

Energy Efficient Windows Costs

High-performance windows offer energy savings in both homes and businesses, reducing utility bills. However, replacing a window requires a high initial investment, and the following are some factors that affect project costs:

• Types : There are different types of windows to choose from and this influences the price. Double hung windows are among the most popular.
• Frames : There are several material options for frames, including vinyl, wood and fiberglass.
• Replaced value : The total cost of new windows will depend on the scale of the project. Consider that a larger project may have a lower unit cost due to volume discounts.
• Performance level : Energy-efficient windows come in various performance levels and this influences their cost. New windows can have double or triple pane, ENERGY STAR rating, gas inserts and special coatings, among other options.
• Installation and labor cost : Qualified professionals are needed to install efficient new windows that ensure proper installation and high performance. The average labor cost for window installation is $38/hour.
• Warranties : Ideally, energy-efficient windows should come with a reliable warranty. This protects your investment and should always be considered when purchasing new windows.

Improve your building's energy efficiency and reduce electricity and gas bills.

Energy Efficient Windows: Key Concepts

Before discussing the different types of windows and frames, it's helpful to familiarize yourself with the terms used to describe them.

Glazing : This is simply the glass used by a window. Describes the number of glazing layers – single, double or triple. It is important to know that the number of layers is not the only factor that determines efficiency. Gas coatings and inserts are also important to window performance.

Low-E : This means low emissivity, which describes the reflectance of the windows. In efficient windows, thin layers of a metallic substance are placed between the panes, which reflect heat rather than absorbing it or letting it pass through. Low-E coatings increase the price by about 10%.

Gas fillers : Gas fillers in windows are placed between layers of glass to improve insulation and reduce heat transfer. Argon and krypton are the most commonly used gases.

Spacers : Spacers are placed between layers of glass to improve insulation. Spacer materials and designs focus on preventing condensation and heat loss.

Window types

There are a large number of windows on the market. Some of the most common replacement home windows installed in homes are as follows.

Window types should be reviewed carefully before a purchasing decision. Each type of window has unique characteristics and features in addition to energy efficiency.

Frame Window

An energy-efficient window will only achieve high performance if the frame itself is also efficient. Frames are the structural backbone of windows, as they ensure proper functioning.

The main types are described below:

Vinyl Window Frames

Vinyl windows are made from rigid, impact-resistant polyvinyl chloride (PVC). PVC is extruded into straight shapes that are formed into window frames, which can be filled with insulation. These hollow spaces make them resistant to heat loss and condensation.

BENEFITS:

• Versatile material
• Accessible
• Good insulators

DISADVANTAGES:

• Not the most durable option
• Not as aesthetic as other materials
• Not as strong compared to other materials
• Cannot be painted and darker tones may fade
• Low-quality vinyl windows are susceptible to warping under extreme heat

Aluminum frames

These frames are made from insulated aluminum profiles with thermal break extruded vinyl and foam to reduce heat loss and condensation. Some finishes, such as painting, protect aluminum from corrosion. Their modern appearance makes them popular in sleek, modern building styles.

BENEFITS:

• Strong
• Low maintenance
• No rot or mold due to exposure to the elements
• Cheaper than wooden frames

DISADVANTAGES:

• Reduced efficiency as heat transfer is greater in metals
• Expensive compared to vinyl or fiberglass frames

Fiberglass window frames

These frames are made from extruded fiberglass sections, very similar to vinyl frames but less common. Because fiberglass is similar in composition to glass, both materials expand and contract together in response to temperature changes.

BENEFITS:

• Durable
• Excellent insulation
• Resistant to corrosive air pollutants

DISADVANTAGES:

• Opaque appearance
• Most expensive material

Wooden window frames

Wooden frames are the most sought after, due to their aesthetic, rustic and cozy appearance.

BENEFITS:

• Durable when properly maintained
• Effective insulators

DISADVANTAGES:

• Requires maintenance
• Expensive compared to vinyl frames
• May undergo severe expansion and contraction with changes in humidity
• Susceptible to rot

Alternative materials for window frames

This section describes other window frame materials that are less common.

Wooden-clad window frames

Wood-clad frames combine the durability of another material with the insulating value of wood. These windows have wood inside and a sturdy exterior made of aluminum or vinyl. This provides weather protection while requiring less maintenance.

Composite Window Frames

Composite window frames are made from a mixture or by-products of wood and plastic. They are similar in appearance to wood frames, are effective insulators, and require little maintenance.

Steel window frames

Steel frames are quite expensive, but more weather resistant than aluminum and wooden frames. They are also a low maintenance option.

Final Recommendations

Determine the pros and cons of each material and decide which option is best for your project. Remember that the performance of window frames also varies depending on manufacturers and their design criteria.

A window upgrade can be the first step in an energy efficiency project, as it reduces air conditioning and space heating costs. If a major renovation is being planned for the property, there is a good chance it will improve the appearance and performance of the windows.