Windows, Doors & Skylights


Windows provide light and ventilation for homes, at the expense of some heat loss (windows let more heat escape than even an uninsulated wall). They also allow air leakage and can allow water leakage if poorly installed or maintained. Windows are relatively complex systems and can suffer problems like but not limited to:


• Panes of glass may be missing, broken or cracked.
• Lost Seal. Double or triple glazed windows may lose their seal.
• The putty or glazing compound holding a window in place may be deteriorated, loose or missing.
• Muntins between panes of glass may be broken or cracked.
• Sashes may be deteriorated as a result of mechanical damage, rot, or failed joints. Sash cords often are broken or missing. Sashes and frames on early metal windows are susceptible to condensation problems.
• Caulking it is not a lifetime material and modest quality caulking has to be replaced every one to two years.
• Inoperable windows are very common and may be the result of paint or dirt in the operating mechanisms or tracks.



Skylights are often installed after the house is built, and installation can be tricky. In addition to cutting a hole in the roof, (and the structural considerations brought on by doing that) leakage must be prevented where the skylight joins the roof covering. This can be difficult, as the skylight almost always presents a curb which will collect water. Low quality and poorly installed skylights are very common and it is safe to say that most skylights have leaked at some point. Home-made skylights rarely perform well. Manufactured skylights should be installed following the manufacturer’s recommendations.


Doors provide a way to enter and exit the house, of course, and can add to the architectural appeal of homes. Doors present a security problem in most houses. Most doors are a source of heat loss, due to poor insulating properties of common door materials (e.g. wood). Air and water leakage around door openings is also common. Some doors add natural light and ventilation (e.g.sliding glass doors) to a home. Exterior doors should be sturdy enough to offer some security, should stand up to weathering, should be fit tightly to minimize air and water leakage, and should include provision for locking hardware.