PVC window FAQs

What are the advantages of a RAL quality-assured PVC window?

The developer or end consumer has the confidence of knowing that all window components and manufacturing steps are subject to regular external quality monitoring. The aim of quality assurance is to demonstrate the suitability of the PVC window for continued use. By the way, the CE mark, in contrast, is not a quality mark, but only confirms that the window corresponds to the properties mandated in the product standard. More extensive information about quality assurance can be found here.

What tests have to be completed for a RAL quality mark?

The quality and test requirements of RAL-GZ 716 require

  1. a comprehensive system description containing all profiles and components
  2. the testing of multiple specimen windows, some of them made in the maximum permitted size, under extreme conditions for direct and conventional glazing.

The performance of the profile system is characterized by the test results obtained.

The Technical Annex to RAL-GZ 716 contains supplementary requirements for components and processes used in a profile system with a quality mark. These are in detail:

  • the consistent quality of the formulation, weather resistance, appearance and dimensions as well as the adherence to the mechanical properties (e.g. heat shrinkage behaviour) of PVC profiles
  • the sealing characteristics of seals and their materials
  • the adhesion and heat build up during the lamination of decorative films
  • the adhesive strength of adhesives for lamination
  • process parameters and adhesive strength during the laminating process

What do I need to remember when buying windows?

When you buy a window with a RAL quality mark, you are always on the safe side. In general, when buying a window you should consider its thermal transmittance value UW, the glazing and its resistance to burglary.

  • The thermal transmittance (known as the UW value) of new PVC windows with triple glazing is accordingly approx. 1.0 W/m2K.
  • Depending on the orientation of the window, triple-glazed windows are suitable for the north-facing side of a building, while double-glazed windows (with a shading option) are recommended for houses facing south.
  • In terms of burglar resistance, windows with resistance class RC 2 offer good basic protection.
  • Where the sashes are particularly large, make sure that the profile, fittings and glass are suitable for such sizes. Talk to your window construction company about this.

Go to your window purchase checklist here (PDF)

What do I do if there are problems with a (new) PVC window?

Contact your window construction company immediately.

What about the thermal insulation properties of the window?

The thermal insulation properties are expressed with the U-value: the smaller the value, the better. Ask for exact details of the window you have selected. U-values can be either measured or computed (according to the EN 10077 standard). The calculation does not necessarily give the same value as the measurement. Find out more about U-values and energy saving here.

What about the leaktightness of the PVC window?

There are tests for windtightness, resistance to driving rain and much more for every window system. Leaktightness is divided into classes. The appropriate class to use will also depend on the height of the building, the direction it is facing, climatic conditions, and so on. If you want disabled-friendly door-height windows, this may entail compromises on leaktightness.

How long will a PVC window last?

Continued suitability for use is the basic idea behind our RAL quality assurance. A window will last approx. 40 years. After being opened and closed 10,000 times, windows must still work perfectly in the approval test. For more on the subject of PVC windows as a sustainable construction product, click here.

Are both white and coloured windows non-fading?

One of the key parts of the approval test is resistance to weathering. For this purpose, white or coloured PVC windows are subjected to a weathering test. After weathering, the mechanical and optical properties as well as the adhesion of the decors must be flawless. For more on the subject of diversity of design, refer to our “Windows for life” booklet (PDF).

What is the correct way to clean and maintain windows?

Regular window-cleaning should be a matter of course. Avoid the use of caustic and abrasive cleaners. Care instructions will be provided when you buy the window and on our information sheet (PDF).

How are PVC windows serviced?

Like all mechanical parts, the fittings need regular maintenance. Follow the instructions for the fittings (e.g. “Lubricate every year”) or in the documents you were given by your window manufacturer.

What happens with old PVC windows and roller shutters that have been removed?

The PVC from windows and roller shutters can be recycled. In Germany, for instance, windows can be recycled through Rewindo GmbH, an initiative of profile manufacturers and recycling companies (www.rewindo.de). Talk to your window construction company. For more on the subject of sustainable construction products, click here.