Which heating system would you choose for our planned new building?

Right Thorsten, but then he has to say it upfront and not come around the back with an additional charge on the promotional price (without knowing whether that suffices with controlled residential ventilation).

Besides, with the values (assuming that the U-value refers to the entire wall and not just the infill!!) the rest should be correspondingly. Then we have a heating load somewhere around 3-4 kW. So made for a heat pump. And then we start calculating plus gas plus controlled residential ventilation plus possibly solar if it really should not be enough, and the LWZ at a reasonable price. 11500 is absolutely absurd as an additional charge....

Correct Thorsten, only he must say it from the start and not come from behind with an extra charge on the promotional price (without knowing whether the controlled residential ventilation is sufficient)

By the way, with the values (assuming that the U-value refers to the entire wall and not just the compartment!!) the rest should be appropriate. Then we have a heating load somewhere around 3-4 kW. So made for a heat pump. And then let's start calculating plus gas plus controlled residential ventilation plus possibly solar, if it really should not be enough, and the LWZ at a reasonable price. 11500 is absolutely absurd as an extra charge....

Absolutely right! Especially the extra charge is "the burner."

Heating load 3-4 kW as an assumption: I also see it that way.

The OP should have everything calculated in full cost accounting, then decide.

I would leave out the controlled residential ventilation: It is a comfort item, which is controversial. You either like it or not. I like it. It is great.

Best regards
Thorsten

The gas connection costs EUR 2500, ST EUR 3500, and with [Bafa] there is a EUR 4000 subsidy for the ground source heat pump. The EUR 900, which makes it even more expensive, would be worth it to me... I personally also assume that even during your 'shorter' usage period, heating with electricity (to operate a ground source heat pump) will turn out to be cheaper than with gas.

I claim that with insulation and size, the heating load should be even smaller than you say. If you don't need the Kfw55 subsidy and 70 is enough, you can still build a house according to insulation standard 55 and save on heating costs without putting too much effort into the technology. Otherwise, as I already said: the lower the demand, the more "irrelevant" the heat generator is; at about 50€ per month and 10% savings, that's a 60 euro yearly difference—you never save the extra cost for an expensive system. I would also separate ventilation and heating, no combined systems. Heating with gas requires a boiler that can model very, very low. Otherwise, the statement that a heat pump is ideal at a heating load of 4kW is nonsense. There are just as many heat pumps that deliver 15kW, even when it's below zero degrees, without heating cartridges.

Hello everyone,

already a thank you for the many responses and the discussion.

The more I talk to sellers of prefab houses, the more I get the impression that they deliberately use their promotions (Proxon at the same price as a condensing boiler) (Proxon, Zimmermann ventilation) and "birthday gifts" (free exhaust air heat pump) to save the installation effort of an exhaust system for the boiler and/or that the systems with heating rods are massively sponsored by the manufacturers.

Whether I later have double the heating costs is completely unimportant to the seller after the signature.

And I have not yet met an "advisor" in the showrooms who does not deceive you with something else.
By now I am so unsettled that I don’t know what to do anymore.... :-(

Frenzi, just simply think calmly.

No one is giving anything away. If he wants to "give something away," then he wants something. That’s the super-duper offer at last-minute bargain price but only valid this week. Forget it. Sellers have to bring in numbers, it’s as simple as that. And especially customers with a high cash ratio are slowly becoming, well, I better remain silent. The sellers sell what they are supposed to. And everything that is luxury is especially liked to be expensive. Very expensive. The more expensive, the higher the commission. For example, the LWZ is offered here on the internet for 11,500. So, was there no heating in it before?

A house, especially when it comes to technology, nowadays is more than just four walls and a roof on top. It’s about concepts and systems, especially in the energy-efficient house sector. But do the sellers there know that?