Substrate preparation for floor coverings

We are preparing to replace the carpet in an office or institution. How do I prepare the subfloor so that everything is in order after the installation?

When it comes to PVC flooring, the subfloor must be prepared very carefully. First and foremost, the right chemistry must be chosen - here, so-called savings can significantly affect the final result. A smoothing compound will make a smooth and hard surface on which we can install the floor covering well. A good screed is a load-resistant surface, and this, in short, affects the life expectancy of our carpet. Of course, I assume from the outset that the screed we are screeding on does not need repairing or buckling.
Another element that affects the quality of the subfloor preparation is the professional team. Knowledge and experience account for a large percentage of a "good finish".

And a few words about the 'carpet' subfloor - there is an opinion that any subfloor is good for a carpet. In my opinion, this is the wrong approach. There is a large group of carpets that require just as good preparation as under PVC.
A good and even subfloor is a guarantee of customer and contractor satisfaction. Then we can give a guarantee for many years of problem-free use without any worries.