Who knows a good aluminum window manufacturer in Saarland?

Thank you for the tips. We consulted with Zenner in Merzig, who sells Schüco windows. Whether Schüco is the "best"... I don't know. They make a good impression, the profiles look top-notch (for laymen). We also want [Raffstoren]. I am already looking forward to the offer.

.. offers far better ones at better prices. For this, I would recommend the company Blasius in Tholey. Price-performance more than TOP. They will be installed with us in 4 weeks, if you want you can come and take a look, we have 26 windows including doors etc... :-)

I dare say (so that everyone can bash me), that probably most windows you can buy are of good quality. Through wrong advice and incorrect installation, you can certainly cause more damage than by choosing the manufacturer. Glass and profiles often come from the same ones anyway.