Generally speaking, when people need to conserve energy, the points of weakness in every household are their windows. Indeed, if those are inadequately sealed, such a house loses much valuable heat in winter and/or absorbs it in summer, straining their conditioner-heating systems just so a home could be warm enough to feel comfy. It is then that changing the old windows out to energy-efficient ones comes along handy.

These may include double-glazed or even triple-glazed windows. As is evident, these are a fairly good option and reduce heat transfer greatly. In such windows, a layer of air or gas separates several panes. This acts as an insulator.