What is important when choosing windows?

As in any other industry on the market, there are many different products on the market when it comes to PVC windows. The easiest way to compare them to cars. Just as we can buy better and worse brands, the same is true for windows. While for many people a window is just a window, they do not realize there are many differences that will have a huge impact on whether they are satisfied with their purchase.

Would you buy a car without checking that it is in good condition just because it's cheap?

Would you buy a computer without checking if it has a good enough specification and will meet your requirements?

The computer or the car are easy to replace. It is a bit worse with windows, because replacing them requires renovation in the whole house. And we buy them with the thought that we will have peace for many years.

If we spend some time at the beginning, get to know the industry a bit and know what to pay attention to, we will definitely increase the chance that we will choose the product and supplier correctly and be satisfied for many years.


1. Profile brand

There are many profile manufacturers on the market, but not all of them have the same long experience or have been producing PVC profiles from the very beginning, so the company's experience does not necessarily mean the length of experience in the window industry.

The company with probably the longest experience in the production of PVC window profiles is the German company Veka, which has been on the European market for over 40 years and has been dealing with window profiles from the very beginning.

Certificates from independent state institutions and notified research institutes

It is important that the complementary products are tested by experts in the industry who have been specializing in construction technology and chemistry for many years. The most recognized institute is IFT Rosenheim in Germany. And if the profiles in which the windows will be produced are certified by unknown institutes, it is worth considering whether it will be the right choice.

4. Profile class

PVC profiles can be produced in various classes that affect their properties, as well as the entire structure of the window.

Class A stands for the highest quality requirements. Profiles of this class have thick external walls (3 mm) and wide chambers (at least 5 mm), which has a positive effect on the strength of the profile and the stability of the entire structure. Before buying, it is worth making sure what class of profiles have been offered to us, because it is not possible to check it in the finished window.

Profiles with thinner walls - from classes B and C:

  1. they do not have the same high resistance to damage as class A and are about 10 to 20% more susceptible to corner cracking
  2. Sound insulation of windows is lower by 1-4 dB, which increases the noise level in the rooms
  3. The thermal insulation of the windows is lower due to the thinner material and the smaller volume of the chambers
  4. The anti-burglary resistance may be lower, because some hinge screws do not hit the steel reinforcements of the profiles (they hit PVC)
  5. The pull-out resistance of the screws used to fix fittings is up to 20% lower
  6. The susceptibility to "conforming" to the stress distribution is higher
  7. RAL mark - awarded by the Association for the Quality of Plastic Window Systems

It means that the characteristics of the produced profiles are identical to those specified in the RAL standards for a given class.

European CE Mark

The CE mark is a window manufacturer's declaration stating that the physical and mechanical properties of the product comply with the requirements specified in the construction design or for a specific project.


1. Choosing a high-quality product

Windows must be manufactured based on a high-quality system of profiles, steel reinforcements, hardware and glass. We buy windows for years, not to replace them in a year or two.

2. Appropriate steel reinforcement

To obtain adequate stability and strength, steel reinforcements are used in PVC windows - both in the frame and the sash. Steel with a thickness of at least 1.5 mm gives the best results. Moreover, the Veka system uses a closed steel reinforcement in the frame, and an open sash with double-folded steel.

Windows made in this way have excellent statics and provide high comfort of use.

3. Seals compliant with the European standard PN-EN 12361-1

Seals should be made of EPDM - a material that is resistant to aging, thanks to which the windows will remain tight. However, there are companies on the market that use ordinary rubber gaskets. They will be cheaper, but is it worth saving on tightness?

4. Certified fittings

Fittings are an equally important element of windows - they are responsible for their functioning. They should be certified under the QM 328 system by the independent institute IFT Rosenheim.

5. Demand precise information about the systems used. Request a technical description and Declaration of Performance.

6.6.Choose the right supplier who will provide you with the necessary information, advise you on the right solutions, has extensive experience and will support you in the entire selection and purchase process!

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