What windows for a passive house?
Passive house windows – a dual role, maximum efficiency
In passive buildings, windows play a particularly important dual role. On the one hand, they must effectively limit heat loss despite their large surface area. On the other hand, properly designed glazing allows for active solar heat gains, supporting the natural heating of the home.
Ecodrew windows, thanks to their extremely low heat transfer coefficient, perfectly fulfill these two seemingly contradictory functions. The advanced glazing used in them achieves a Ug value as low as 0.4 W/(m²K), making them an ideal solution for passive houses.
Advantages of windows designed for passive houses
To meet demanding energy efficiency standards, passive house windows are equipped with triple glazing and frames with excellent insulation properties. Since the frame accounts for as much as 30–40% of the entire window opening, its quality is crucial for achieving a high level of thermal protection.
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Glazing with a very low heat transfer coefficient
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Frame with high insulation properties
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Thermally optimized edge sealing
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Passive house windows – optimal positioning
To fully utilize solar energy, the placement and orientation of windows in a passive house must be carefully considered. Properly planned glazing allows the building to retain more energy in winter than it loses, while in summer it protects interiors from excessive overheating.
The most beneficial solution is to place large window areas on the south side. In winter, the low-positioned sun provides maximum natural heat gains, while in summer—when the sun is higher in the sky—most rays are reflected, reducing overheating and usually eliminating the need for additional solar protection.
Windows facing east and west, on the other hand, may lead to excessive indoor heating, especially in the morning and evening during summer when the sun is low. In such cases, appropriate shading solutions should be considered.
As a general guideline:
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east and west-facing windows transmit about 60% of the solar energy provided by south-facing windows,
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north-facing windows – about 40%.
To meet passive building standards, it is recommended to keep the maximum deviation from the south direction within 10°.
It is also important to consider local conditions during design: the actual sun path throughout the year, shading from other buildings, trees, or terrain features. These factors are crucial for the building’s final energy efficiency.