Underfloor heating or air heating in the new building? (KFW55)

Hello everyone!

Our construction project is becoming more concrete, and so we have been pondering for some time now about which heating system we want to use.
There are these two options to choose from:

Schwörerhaus "Wärme GewinnTechnik" WRG134HK:

[*]Air-to-air small heat pump (integrated into ventilation system)
[*]Additionally, small PTC heating elements at the outlets
[*]Summer bypass possible (slightly cooling effect)
[*]Hot water via: "Drinking water heat pump Aerotop DHW250"
[*]Water tank: 250l with electric auxiliary heating
[*]Costs approx.: 12k euros

Underfloor heating:

[*]Air-to-water heat pump Buderus "Logatherm WLW196i IR"
[*]Here too, there should be an option for a slightly cooling effect
[*]An annual performance factor of ">=4.5" is specified
[*]Hot water also via this unit
[*]Water tank: 300l (nothing is mentioned about electric auxiliary heating)
[*]Costs approx.: 25k euros

Additionally, a few details about our house:

[*]Floor area: 74.07 m²
[*]Usable area: 116.29 m² + 69 m² basement
[*]Built on a slope facing south
[*]Still close to the Sauerland => winters can be cold, wet and long

Many details to consider, and now the question is: How would you decide... and why?
What would you recommend?

Underfloor heating... air is a poor medium for heating or cooling...

What you apparently save in initial costs you will sooner or later put into the heating... and when selling or renting out later, the house will be valued lower because there is no "real" heating.

Definitely option 2! Option 1 is initially cheaper, but later it will eat your hair off your head with the electricity costs!

I do not yet see Variant 1 in KFW 55 construction either, that is more for passive houses with negligible heating loads. Otherwise, the air-to-air heat pump turns into a de facto electric heater with very low comfort.

All right, thanks for your assessments so far!

We had similar concerns regarding the air heating. In addition, you often read about dry air... especially when it's cold outside.

At first glance, it is just unbeatable cheap, but as you already say: probably not in the long run after all :-/

Do you have experience with the offered [Buderus LW heat pump]? Is the device any good?

I personally have no experience with this Buderus device; however, I am professionally somewhat knowledgeable about heat pumps: These split devices are all somewhat similar in terms of COP and such. So, in this regard, it is not really important which manufacturer you choose. Perhaps for future repairs, one should consider one of the very large manufacturers, simply so that they still exist after 10 years. Much more important is an overall system precisely matched to the actual heating and hot water demand of the building. And a heating technician who is really already well versed in sizing, installation, etc., and who lives within a reasonable distance so that they can quickly be there in case of a malfunction...