Windows, Doors and Skylights

Everyday Tips

  • In the winter, open curtains to allow sunlight to warm your home. In the summer, close curtains (especially on the west-facing windows) in the afternoon to keep the house cool.
  • Shut exterior doors completely. If it’s closed but not latched, it can let heat inside during the summer and outside in the winter.

Enhancing Existing Windows and Doors

  • Install exterior overhangs or awnings in order to keep the strongest rays of the hot summer sun from entering.
  • Use your landscaping to keep your home warm in the winter and cool in the summer. Well-placed deciduous trees on the west and northwest side of the house can reduce cooling costs in the summer. Planting trees on the south side can block warming rays that would help heat your home in the winter.
  • Seal air leaks around windows using either rope caulk or a caulking gun.
  • Install storm windows. Options include vinyl film, rigid plastic or combination storm windows. Consult your local hardware store or window dealer for the best option.
  • Install weather stripping around exterior door frames to ensure a tight seal when the door is closed.
  • Install door sweeps at the bottom of the door to reduce airflow.
  • Consider installing a storm door in addition to your exterior doors.


  • Purchase ENERGY STAR® windows, doors and skylights. If your home has only single-pane windows, new ENERGY STAR windows will provide a noticeable difference in comfort and heat loss or gain.
  • Look for double-pane windows with a low-e (low emissivity) coating, insulated sashes, spectrally selective coatings and an inert gas filling. Look for a U-value of 0.30 or less and a Solar Heat Gain Coefficient (SHGC) of 0.30 or less. Lower numbers are better. Consult the National Fenestration Rating Council label (NFRC) to understand the performance features of windows and skylights.