Aluminum windows are more durable than wood, and are
thinner, lighter, and easier to handle. But aluminum is a poor
insulator and in cold weather, and loses more heat to the
exterior than wood. Most recent aluminum windows are
manufactured with a thermal break, a vinyl or rubber strip
that separates the exterior and interior aluminum parts of the
window. The thermal break reduces the movement of cold
from the outside to the inside of the building. Most
commercial applications still specify aluminum windows