Air-to-water heat pump sizing in new construction

Hi, I found something else in the thermal insulation calculation. Is that the Ht value???

Best regards

Ht=0.28

I'll compile the data:

Ht = 0.28
NAT = -11.49
Building envelope area: 559.65 m2
Building volume: 726.44 m3
Heated air volume: 552.09 m3
180 sqm living area with underfloor heating. Approximately 230 sqm usable area.

Desired temperature: 20-21°C
Occupants: Currently: 2+1 child + possible granny flat (let's assume a max. of 5-6)
Ventilation: None

Results in 6.5 kW without ventilation for me.

0.28 is just about KFW 55 but certainly not much better. I don't find it bad but not exactly great for a wooden house.

Is the granny flat already included in the heated volume?

Is the granny flat already included in the heated volume?

Yes