Windows Made of Aluminum
Windows manufactured from aluminum are better suited to commercial buildings rather than a home. The reason for this is aluminum lends itself to the production of very large windows where structural stiffness becomes a concern. For the average home, alternative materials such as vinyl have plenty of strength to do the job. In addition other, non metallic materials, offer far greater energy savings in that they do not conduct heat or cold the way a metal such as aluminum will.
There are various techniques used to increase the energy efficiency of aluminum such as thermal breaks made up of plastic strips but even these do not make aluminum a logical choice for the home owner.
One application of aluminum in modern replacements is through "cladding". With this the manufacturer will cover the exterior of a wood window thus increasing the outer protection. Thus you can have a traditional look, energy saving construction material, and exterior free maintenance.