House costs per KFW level per m²

The additional costs for the next higher KfW ratings are not covered by the higher subsidies, that much can already be said.

For me, it exactly worked out. ;)

But it often depends on things you want anyway, such as: photovoltaic (always makes sense), controlled residential ventilation (is a great thing), insulated roof (makes the attic usable), ...

Is there currently still a rule on how high the price per m² is for a house with KFW level 40 and with KFW level 55? [...] We can apply for a plot where you get more social points for building a level 40 house. Through this, we want to see whether we can even afford the additional points or whether we should continue to plan with KFW level 55 (minimum level in the new development area).

Everything you can read somewhere about average construction costs either relates to reality with all insulation levels mixed together as they occur in the total of all constructions in a year, or to the legal building standard. Additional costs are not calculable because the ways to reach the next level are too diverse. Furthermore, although many construction companies at least regularly build KfW55 or even offer it as standard, KfW40 can be problematic: in the "more affordable" case they only know the most expensive way to get there. Not infrequently, they do it so rarely that they do not really have experience with it and later justify construction damages in the unfamiliar details. In my opinion, KfW40 is explicitly made for the target group "we carry our above-average salary to the organic food store" (who, however, not rarely arrive there in an SUV). I find it quite cynical to credit more social points for this because this offer appeals to a better-earning group of applicants. If the KfW40 plot applicant social bonus points decide whether you even get into the draw, I recommend continuing to search instead. I would fear that the next step would then be kindergarten place bonus points for vegans.

Is there currently still a rule for how high the price per m² is for a house with KFW level 40 and KFW level 55?

There is no rule.

Are there already new benchmark values here?

There are benchmark values, which are very different. One includes additional construction costs, another does not. An architect calculates differently than a forum participant.
And with the latter, one should always compare the same reference source as a measure, otherwise you calculate with apples and oranges. The reference point should rather be the valid Energy Saving Ordinance, since every builder achieves their 55 or 40 differently and these means are already very different. The surcharge for an upgrade in a car also costs less for a Polo than for a Mercedes.
Since you entered the building desire phase last year and already received values back then, I would rather have thought that you are the one who can give us current prices.
I often say here: the builder has to do their homework about house prices and co themselves, otherwise they don’t get a feeling for it. The result is a miscalculation that even a forum cannot check or correct, since important data (expert opinions, regional prices, personal works contract and personal wishes) ultimately only come together with the builder.
I could now tell you 2300€/m², but that only applies to a plain solid house with several + (the usual suspects like incidental construction costs, Kfw70, plaster, painter, exterior, carport and furniture) underneath.
Whether the value fits regionally for you, you have to find out.

Hi,

I can currently give you an example for which we have a concrete offer. "Fertighaus," timber frame, just need to put in furniture.
Construction site: economically strong region in northern BW.

House approx. 160 m2 without basement. Simple rectangular architecture without bay windows etc. Gable roof. Air-water heat pump
KFW 55 approx. 2570.-

Kfw 40 + approx. 2820.-

Additional cost approx. 40,000
As already mentioned. Better insulation. Controlled residential ventilation and photovoltaics with storage.

In my opinion, KfW40 is explicitly made for the target group "we carry our above-average salary to the organic store" (who, however, quite often arrive there in an SUV). I find it rather cynical to assign more social points for this, because this offer appeals to a better-earning applicant group.

Now, hold on, you can't say that so generally.
If a controlled residential ventilation system is explicitly desired anyway, then it can very well be possible to use the additional funding to upgrade from 55 to 40.

And for a zero-sum game, of course, you then take the better insulation with you.

How do you want to determine a price per square meter at the KFW standard?
Is the type of heating specified?
Is it specified whether you build a basement?
Is it specified whether you build monolithic, timber frame, or something else?
Is it specified whether you have a finished attic?
Is it specified whether you use 30cm or 120cm tiles?
Parquet or laminate?
Network?
Plaster Q2, 3 or fleece?
Motor lock, garage or carport?
Etc, etc, etc, and so on, etc.

KFW has something to do with energy demand or energy emissions.
What makes your house expensive or not in the end is the equipment.
You can certainly build KFW 40+ for 3,000€. But you can also build according to the Energy Saving Ordinance (KFW70) and spend 3,000€. And more or less.

I’m afraid this question cannot be answered like that.

Edit: in the end, KFW is just calculation anyway.