Passive house windows

Aluminium windows from heroal are real energy savers and are therefore certified by the Passive House Institute Dr. Feist for passive houses.

Passive house windows

Certified passive house windows as energy savers

Insufficiently insulated windows often result in costly energy loss. Aluminium windows by heroal minimise this energy loss with thermally separated profiles, special fitting technology and an optimal profile geometry. Replacing old windows is not only an investment in more comfort, it also pays for itself in the long run through savings on energy costs. The modular structure makes it possible to individualise the planning of your windows with insulation classes ranging from highly insulated to passive-house certified. A passive house has no active heating system and is heated only by passive energy sources. This allows for a reduction of up to 75% in heating energy. Passive house windows are an important component in achieving the passive house standard, as windows are one of the main sources of lost heat.

What’s so special about heroal passive house windows?

Very low design depth

The window system heroal W 77 PH stands out for its excellent thermal insulation features, while at the same time offering a very slim design depth of only 77 mm. In addition, it has been granted passive house certification by the independent institute PHA (Passive House Institute Dr Wolfgang Feist).

100 % foam filled

The foam filling process developed by heroal ensures that the insulating chamber is 100 % filled with PU foam. Because of this, ideal heat insulation values can be achieved, even with slim frame widths.

Insulating strip geometry

The innovative geometry of the insulating strips reduces the flow of energy and conduction of heat. With a profile design depth of only 77 mm, heroal windows achieve U-values meeting passive house standards.

Components of heroal passive house windows

There are many components that make the heroal passive house window a particularly effective energy saver. These include the factory profile compound, the heroal foaming process, a special thermal insulation glass, patented thermal break technology, an optimised isothermal curve and themodular insulation zone structure.

heroal's own profile composite

heroal's own profile composite - heroal is the only company producing thermally insulated aluminium-PVC-composite profiles under external monitoring (ift Rosenheim, testing institute).

Modular composition of sealing zones

Modular composition of sealing zones - Thanks to the modular composition of sealing zones, individual customer requirements become possible - from high thermal insulation to passive house suitability.

Optimised isothermal curves

Optimised isothermal curves - Due to optimised isothermal curves, the thermal conductivity via the edges of the sealed glass pane is considerably reduced.

Low-E glass

Low-E glass - To make sure that valuable thermal energy is not lost via the glass pane, our specialised partners will be pleased to give advice on the suitable insulating glass for your requirements. Depending on the required thermal insulation, coated Low-E glazing or triple glazing may be used.

heroal foam-filling process

heroal foam-filling process - In their modular insulation areas, heroal aluminium composite profiles are filled with PU-foams. The special process developed by heroal ensures that the insulation chambers are 100 % foam-filled, which leads to a better thermal insulation than other processes.

Patented insulating strip technology

Patented insulating strip technology - heroal's innovative insulating strip technology combines high capacity with minimal loss of heat. The geometry of the insulating strips reduces the energy flow and thus also reduces heat conductivity significantly, exceeding the current requirements of EnEV, the German energy saving regulation, by far.

heroal passive house windows at a glance

Passive house certification by the Dr. Feist Passive House Institute

heroal passive house windows are certified by the Dr. Wolfgang Feist Passive House Institute. As an independent body, the Institute tests and certifies products for their passive house efficiency levels. The Institute tests all products according to uniform criteria, which ensures that they can be accurately compared.

The passive house window heroal W 77 PH achieves a Uf value of 0.78 W/m²K and a Uw value of 0.79 W/m²K with an installation depth of 77 mm and a face width of 180 mm, which makes it passive-house certified – tested by the Dr. Feist Passive House Institute (Uf value ≤ 0.80; Uw value ≤ 0.80). If you would like to have a narrower face width, the heroal W 77 PH can achieve a passive house Uf value of 0.80 W/m²K even with a face width of 120 mm.


  • What are the requirements for passive house windows?

    In order to achieve passive house certification, windows must not exceed a UW value of 0.8. Since the introduction of the Energy Saving Ordinance (EnEV), the U-value (heat transfer coefficient) has replaced the k-value to provide a uniform, Europe-wide designation. This value describes how much energy or heat per m2 of window area can escape from the inside of the building to the outside. A passive house window has no specifications in regards to materials. It makes no difference whether the windows are made of wood, plastic or aluminium. In principle, any material can be processed into a passive house window as long as it meets the U-value requirements. Passive house windows are certified by the Dr Wolfgang Feist Passive House Institute. According to this institute's standards, the entire window, including the glass and frame, must not exceed a U-value of 0.8. The window should have a g-value of ca 50%. The UW value represents the thermal transmittance of the frame (Uf) and the glass (Ug).

  • Where can I buy heroal passive house windows?

    You are looking for suitable windows for your passive house? Certified heroal passive house windows are available from our heroal specialist partners. They manufacture windows individually for your passive house. Our experienced specialist partners will provide you with advice in advance, and take care of a professional installation of your heroal passive house windows. Please use our heroal specialist partner search and find a fabricator in your area easily and fast.

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  • What does the U value for passive house windows mean?

    The U-value (heat transfer coefficient) describes the efficiency of a window in terms of thermal insulation and heat transfer. Since the introduction of the German Energy Efficiency Directive (Energieeinspar-Verordnung, EnEV), this has replaced the k-value. This allows the measured values to be compared across Europe. The U-value indicates how much energy per m2 of window area can escape from the inside to the outside. A lower heat transfer coefficient means that less heat can escape through the window, representing a higher level of energy efficiency. The thermal transmittance of the entire window (UW) is divided into a Uf and a Ug value, where the Uf value reflects the thermal transmittance of the window frame and the Ug value reflects the value of the glazing

    • Uw(w = window): Heat transfer coefficient of the entire window
    • Uf(f = frame): Heat transfer coefficient of the window frame
    • Ug(g = glazing): Heat transfer coefficient of the glazing

  • What does the g value for passive house windows mean?

    The g-value (solar energy transmittance factor) describes the total energy permeability of a transparent component such as window glass. The g-value consists of two components: the proportion of solar radiation that passes through the window and the heat emitted by the glass to the interior by solar radiation. A g-value of 1 represents a heat gain or an energy transmission of 100%, which represents a complete conversion of the incident solar energy. Windows normally achieve a g-value of 0.85. This means that 85% of solar energy can be converted directly into heat. A more energy-efficient triple glazing achieves a g-value of 0.55. This means that the interior is not heated as quickly by the solar energy. This is particularly advantageous in the summer, as the interior of the building stays cool longer.

  • Who installs heroal passive house windows?

    Professional installation of your passive house windows ensures that they can achieve the highest possible energy efficiency. heroal has more than 3,500 installation professionals throughout Germany. They will help you to select your passive house windows, deliver them quickly and conveniently and provide professional installation. On request, our specialist partners can also remove your old windows. Use the heroal partner search tool to find a partner near you in just a few quick steps.

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  • Are passive house windows suited for both old and new buildings?

    Passive house windows are suitable for both existing houses and new construction projects. Even if you are not trying to achieve passive house certification, installing windows that meet the passive house standard improves the energy balance of your house and reduces heating costs. Thermal images clearly show that inadequately insulated windows are the primary source of energy loss. Binding minimum energy efficiency standards for windows were not defined until 1995. As a result, windows installed before 1995 generally have a significantly lower energy efficiency standard than modern windows.


Advantages of heroal passive house windows

With heroal passive house windows, you can be sure of the highest energy efficiency. Innovative technologies make it possible to achieve small construction depths and narrow face widths with superior U-values.

  • passive house certified
  • modular insulation zone structure
  • optimized isothermal progression
  • patented thermal break technology

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