However, some marketing claims go so far as to suggest that “overall home energy costs will be reduced by up to 50%.” Others state that replacement windows “will eliminate mold and condensation.” Consumers should understand that such claims do not apply in all window replacement situations, and in some cases these claims are misleading and deceptive.
The FTC has recently announced five settlements with marketers of replacement windows over charges that their savings claims were deceptive and not backed by reliable scientific evidence.
Under the settlement, companies that sell replacement windows in numerous states will have to stop making exaggerated and unsupported claims about the energy efficiency of their windows, and how much money consumers could save on their heating and cooling bills by having them installed.
The actual energy savings realized by replacing windows depends on various factors, such as the condition of the existing windows, how well the house is insulated, the amount of interior space in the home, and the climate zone where the home is located. Given these diverse factors, it is impossible for a company to make accurate assessments of energy savings on a generalised basis.
What are realistic savings estimates from replacement windows?
Since there are many factors which affect the amount of energy savings from replacing windows in a home, the figures below are not meant to represent actual savings in all situations. They do, however, provide a point of reference for homeowners in calculating the cost/benefit of installing replacement windows.
Replacement window savings during the heating season:
Annual heating energy costs for a typical house in Boston, MA.:
- Single-pane window: $1625
- Double-pane window: $1365 16% savings
- Double-pane Low-E window: $1283 21% savings
- Triple-pane Low-E window: $1202 26% savings
Replacement window savings during the cooling season:
Annual heating energy costs for a typical house in Phoenix, AZ.:
- Single-pane window: $1250
- Single-pane, tinted window: $1175 6% savings
- Double-pane, thermal break window: $1100 12% savings
- Double-pane, thermal break Low-E window: $812 35% savings