Yes, we don’t have screed, but we also don’t have concrete ceilings; instead, we always have wood, even for the basement floor (since we have a wooden basement). On the wooden ceiling lie green mats for insulation and protection, on top of which came calcium silicate bricks (to prevent swinging and for sound insulation), simply just laid. Only the pipes for ventilation and wastewater, etc., which lie in the floor, had the calcium silicate bricks removed, the pipes laid, and then concrete was poured there.
On the calcium silicate bricks then came those green mats again, and on top of that the panels for the underfloor heating, which were essentially laid into a "wooden frame." Then the natural parquet was laid on top, and it was oiled:

Here you can see the openings left in the calcium silicate bricks for the pipes – and beneath that the green mats lying on the wooden floor
Then the pipes were concreted in:

And that really is the only concrete we have in the house!
On top of that came those mats again:
And this is how it looked with the mats for the underfloor heating:

There is surely also nice insulation material without the loops for underfloor heating
It looks like this on a large scale:
And on top of that came the solid wood parquet:
Initially natural:
Then oiled:
