Gas or Air-Water Heat Pump

Hello,

For a long time we have been reading on the internet about heating..
We are desperate, I hope you can help me.
We are building a single-family house in Berlin Mahlsdorf.
125 sqm
It is a 30 cm masonry (including insulation), it is being built with ytong.. prefabricated system components.
Completely with underfloor heating without a basement.
Gable roof.
On the internet, I once did a quick test for the heating load, it was 8.6 (realistic)

We have an offer from the house builder for a gas condensing boiler with heat recovery.

Cost-neutral offer with air-water heat pump from thermia atec total 9

With the air-water heat pump we would also save the house connection and we would receive a credit of 2500 for the heat recovery.

Please help me with the decision..
If you need more details, please tell me which ones. Thank you in advance.

125 sqm new building with 8.6 kW heating load !?
Air-water heat pump is okay with a 4500€ price advantage - I assume the VAT is then dropped, correct?

Is the heating load too low? I calculated it with an online calculator.

Well, the price advantage would be around 2,000 with a heat pump.

What does ST mean?

Thank you for the quick response.

Heating load far too high. With more sqm and a basement according to kfw70, now standard, I have about 4kW heating load (including hot water), location NRW.

Hello,

It is a 30 cm masonry (including insulation) built with Ytong... system prefabricated parts.
Completely with underfloor heating without basement.

30 cm - Are you kidding us...?

I once did a quick heating load test on the internet, it was 8.6 (realistic)

Are you an energy expert or what makes you assume that you could calculate the heating load...?

We have an offer from the house builder for a gas condensing boiler with heat recovery.

There is no gas condensing boiler with heat recovery, but there is certainly a controlled residential ventilation with heat recovery!

Please help me with the decision..

Stop trying to educate yourself on the internet and seek professional support... of course that costs quite some euros. Is there no buffer for that in your loan: buy a condominium.

By the way: it would be helpful if you would observe the registration regulations! Please enter your profession!

Rhenish greetings

Somehow every 2nd thread here is about this. Already read a lot on the internet but haven't managed to look up anything here in the forum. Why don't people get advice from the experts?