noun
double glazing; double-paned glass
Refers to window glass consisting of two panes with a sealed air gap for insulation or soundproofing.
このマンションは二重ガラスなので、外の騒音が気になりません。
This apartment has double-paned glass, so outside noise isn't bothersome.
冬の暖房費を抑えるために、窓を二重ガラスに交換した。
We replaced the windows with double glazing to reduce heating costs in winter.