Check out my latest post on the Aborus Efficiency Journal:
Windows are one of the most important elements of a building envelope. They provide views to the outdoors, and bring in sunlight while protecting the building interior from the elements. Unfortunately, windows tend to do a poor job of resisting the movement of heat. Compared to an opaque wall, which will likely have three to six inches of insulation, windows are weak thermal insulators and usually make up the weakest link in the building envelope. Given that windows take up increasingly large fractions of walls in modern buildings, this presents some challenges to building designers who wish to provide a high performance building envelope.