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Windows & Doors

Windows, doors, and skylights are often a weak link in home construction, accounting for a significant portion of a home’s heat loss in the winter and heat gain in the summer. 

Any opening in the home, such as a door or window, will be far less efficient than the surrounding wall structure. But an opening doesn't need to become a major source of air leakage in your home. Simple maintenance and inexpensive repairs --like caulking, weather-stripping, and painting --can extend the life of your doors and windows and save energy! 

Repairing your doors and windows 

Here are some common window and door problems that you can fix yourself: 

  • Replace or seal damaged parts. Cracked or missing panes are obvious places for energy loss. In a pinch, you can also seal with caulking as a temporary solution. 

  • Improve air sealing. The gap between the jamb and the framing may be empty or stuffed with fiberglass insulation. You can seal this area instead with door and window spray foam or caulking. If access to the space is not possible, you can also apply a small bead of paintable caulking to the joint between the trim and the wall. The quickest, single-season solution (good for renters) is to apply shrink-wrap film on the inside to stop air leaks. 

  • Replace missing hardware. Latches, hinges, and the operating parts for crank-out windows can become loose or damaged through use. Often a simple tightening of the screw will do the trick. 

  • Make sure rainwater is diverted properly on the home’s exterior. Water that seeps into the wall cavity can lead to rots and voids, which allow air leaks. 

  • Replace worn weather-stripping. Weather-stripping prevents air infiltration around windows and doors by sealing the gaps between the frames and moving parts when they’re closed. You should weather-strip all doors leading to unheated areas, like the attic, garage, and unheated basement. 

Replacing your doors and windows 

Buying new doors and windows can be confusing at first, because there are so many options today. Shopping for an energy-smart option becomes much easier, however, when you look for two important labels that will inform you about the relative efficiency of each option. 

The NFRC Label rates performance 

The National Fenestration Rating Council (NFRC) is a non-profit organization that provides consistent energy and performance ratings of windows, doors, and skylights. Its ratings are based in several categories: 

  • The U-Factor indicates the ability of a window to conduct heat in the winter. The lower the number, the better the energy efficiency (we recommend 0.3 or less). 

  • Solar Heat Gain Coefficient measures the window’s ability to reduce heat in the summer. In Minnesota, we recommend a balanced value of 0.5. 

The ENERGY STAR® label guarantees energy efficiency 

The U.S. Department of Energy and the Environmental Protection Agency developed the ENERGY STAR® designation for products meeting certain performance criteria. Since the energy performance of windows, doors, and skylights can vary by climate, product recommendations are given for specific climate zones. 

Cost-effective alternatives to window and door replacement 

Before you invest in complete replacement of your windows and doors, you may want to consider less expensive alternatives:

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