First the floor then the interior door or vice versa?

Hello,
I bought a terraced house from a property developer. Since I would like to have sound-insulating doors, I cannot use the door company provided by the developer. They only install the standard, planned doors.

Now I am considering not having any doors installed at all and having them installed by a company after handover. At the same time, parquet still needs to be laid everywhere. How do I best organize the work?

And does anyone have experience with acoustic interior doors? I would like to have them on the bedrooms and on the ground floor in the "living room." The "living room" will also be a consultation room for a psychological practice. The house will be a flat-share house for ["Mittelalter"] (mid-40s). I don't want to know what my roommate does in the bedroom.

Do you have a controlled residential ventilation system? If yes, the changed airflows must also be considered (no overflow but separate supply and exhaust air). Are the walls highly sound-reducing? With Ytong or thin drywall, the door is also useless. You have to tackle this as an overall concept and not with individual adjustments... Have you asked this question recently? Usually the floor goes in first and then the door frames.

Thank you, Rick. The question about the doors I have already asked. Now it is mainly about the correct order and the consideration whether to do the floor first, then the doors, or vice versa. Because if I had taken the doors from the builder, then it would have been doors first, then the floor to be laid by myself. Yes, the house has [Kontrollierte-Wohnraumlüftung (D)]. My consideration is what is the most cost-effective: doors through the builder or later externally. Even if they were normal doors and not acoustic ones.

Then you would have to change the controlled residential ventilation! Doors with higher soundproofing do not come with overflow. From SK2 it gets quiet. You will receive a small credit from the developer if you remove the doors and frames from them. Good doors also cost good money... But that way you would only pay once. What is the wall structure like at the affected spots?

The wall construction in the interior walls is partly made of the red quick blocks, partly of Ytong. The thickness is, I believe, 12cm + plaster. Maybe I'll just leave the doors as planned and it will somehow be okay. Each door costs about 220 euros including installation (painted then 370 euros) + VAT.

To be honest, I would do the same if I were you. See how it behaves then. You can always install a "more stable" door leaf without much effort later on...