https://glawindows.com/passive-house-windows/

Windows in passive houses are tripled glazed and frames are also very well insulated in order to fulfil the high requirements on thermal insulation. The window in a passive house plays an excellent role in two ways: firstly, the heat loss can be reduced despite large glass areas, and secondly, windows open up possibilities for heat gain through solar irradiation. Our passive house windows offer exceptional thermal performance and long-term durability for your passive house build or retrofit.