Energy efficient windows help homeowners lower energy costs, including the costs of lighting, cooling and heating the home. As outlined by the US Department of Energy, selecting the best energy efficient windows for your home depends on factors of the home design, the climate in which it is located, the type of windows being installed and factors of their placement, such as shading, orientation and glazing.
Because of this variation in criteria, the top energy efficient windows for homeowners under some circumstances may not be the same as the top energy efficient windows for homeowners in other circumstances.
With that in mind, whether you're building a new home and incorporating energy efficient windows into the original design or you're remodeling your existing home to be more energy efficient, the following is a breakdown of the five best types of energy efficient windows for homeowners in the most common climate areas and house designs. To find specific manufacturers, models, and pricing, the Efficient Windows Collaborative has a Window Selection Tool that is incredibly helpful for finding the right energy efficient windows for any specific conditions.
In reading these comparisons, you'll come across two terms utilized in evaluating the energy efficiency of windows:
U-Factor: a measurement of a window's ability to keep heat from escaping
Solar Heat Gain Coefficient (SHGC): a measurement of passive solar heat passing into a home through a window, which can be beneficial for heating purposes but detrimental for cooling purposes
While these are by no means the only measurements of a window's energy efficiency (others include Visible Light Transmittance, Air Leakage and Condensation Resistance) they are two of the most common, important and convenient for basic comparison.
Lastly before proceeding to the specifics on the top energy efficient windows themselves, an important note regarding energy performance ratings of energy efficient windows: ENERGY STAR®, the generally accepted gold standard of energy rating authorities, gives minimum energy performance ratings for energy efficient windows. However, while these are an excellent guideline and a helpful start in determining the energy efficiency of home windows, they are incomplete, and therefore insufficient, determinants of the actual energy performance characteristics you'll need from your energy efficient windows, as they take only climate into consideration but not home design elements, such as the types, size and placement of the windows selected.