Most basically, a window is an opening in a wall or roof that allows the transfer of light and sometimes air. Initially windows were simple holes that were then filled in with cloth or animal hides, eventually replaced as time went on by glass and then glass separated into panes. Today, there are many important factors to consider when selecting a window.

Windows may account for a major source of unwanted heat loss or gain in a structure. The purpose of windows is to bring in daylight and allow ventilation. A completely windowless structure would prevent heat loss, but would run up the lighting bill. There is a direct connection between daylight and ventilation and personal health. Daylighting is also a consideration of many codes. Current technology allows for windows to be more energy efficient than in the past.

Passive ventilation and natural cooling are combined with mechanical systems to create healthier indoor environments and even better energy efficiency.

Water leakage at windows and doors is a costly problem that can lead to mold. Here are some mold-resistant construction techniques from an expert.

With today’s emphasis on “green” and the high cost of heating fuels, windows represent an important factor in building construction. From the “top floor, corner office,” to the popular Apple store on Fifth Avenue in New York, to the proposed 3-story all-glass lobby for a Boston office building, we all love to have ample outdoor light shining in — but be properly protected from the elements. The following are some recent innovations when it comes to windows.