Heating concept for new construction based on gas

At least that's how I understood my provider. Gas probably would not be sufficient despite controlled residential ventilation. Maybe one of the experts here can say something about it.

You combine an energy producer that can generate reasonably high temperatures (gas) and use it to produce low temperatures of 30° for the underfloor heating, and the energy producer that operates particularly economically at low temperatures (heat pump) is used to generate the hot water. Somehow confusing.

We have a gas condensing boiler with a solar system and buffer storage. Independently of that, decentralized ventilation with [WRG]. We thereby achieved KfW55.

It would be helpful if the wall structure is always mentioned.

I believe Kfw55 only works with a gas condensing boiler with solar as well as controlled residential ventilation and in our case a 36èr T7 MW.

Timber frame construction with cellulose insulation, insulated base slab (glass gravel). H'T 0.235 W / (sqm/K) for the envelope area.

I thought so...