Single pane windows, also known as single glazed windows, consist of a single piece of glass. This window type used to be the norm in residential construction, and today, it is still common in many older homes. As a recommended first step, inspect your windows to determine whether they are single or double pane since this can have a huge factor in your energy savings.
Double pane windows are now the most common window type which have either air or, for more efficient types, an inert gas, sealed in between the pieces of glass. By preventing the formation of convectional currents, these window types provide substantial energy savings, ensuring that the thermal gradient between the inside and outside of the window is minimized. Energy Star studies show that replacing single pane windows with double paned ones can save between 21% and 31% of heating and cooling costs of a typical home.
Triple-pane glass windows are the most energy-efficient models on the market. With the extra pane of glass, they moderate temperatures inside for optimal comfort in every season. It is important to note that while triple pane windows are more energy efficient, they are also typically substantially more expensive and heavy - which means they can impact your home's structural elements and therefore, need proper planning for integration into an existing home.
Glazing - Low-E
Low-E glaze, also called "Low-Emissivity" glaze, is a type of glass that is coated in metallic oxide. This invisible layer prevents heat from passing through the glass by reflecting UV rays back into the atmosphere. Low-E glaze is often used on double pane and triple pane windows to increase the energy efficiency without adding to the weight of the window. Windows with Low-E glaze cost slightly more than windows without, but reduced utility bills help homeowners recover those costs in 5 to 10 years. In addition, there are other benefits to Low-E glaze which can help justify the cost. For example, your furniture is less susceptible to fading, and artwork around your home is protected from the damaging rays of the sun.
Inserting refers to changing your existing window. This is a cheaper option that allows residents to get the latest window performance features while minimizing disruption to their home. Insert windows preserve the original frame, exterior trim, exterior siding and interior casing. Typically this is only effective for new homes with least chance of leakage and therefore, before you make a decision to change the inner components, inspect your window and the area around it for any breaks or cracks that can interfere with the integrity of the window.
Existing Exterior Trim
Existing Window Frame
New Insert Replacement Window
1. Modernize (n.d.), Windows - Energy Efficient. Retrieved from: https://modernize.com/windows/energy-efficient.