Is estimating KFW55 useful, or is the Energy Saving Ordinance preferable?

Since we didn't want a heat pump and controlled residential ventilation anyway, we built according to the Energy Saving Ordinance and executed the areas that were important to us at a higher quality. (Better insulation and windows).

I don't think there is one right way of looking at it. Everyone has their own demands for their house :)

Since we didn't want a heat pump and controlled residential ventilation anyway, we built according to the Energy Saving Ordinance and executed the parts that were important to us with higher quality. (Better insulation and windows).

I think there isn’t one right perspective. Everyone has their own demands for their house :)

However, if you can achieve the KfW55 standard without a heat pump and controlled residential ventilation with additional costs below €10,000 (which should be doable), then I currently don’t see the point in NOT building according to KFW 55?

However, I don’t know if this is even possible without a heat pump? It depends on what you have installed.

The only issue would be the KfW loan interest and the repayment rate --> However, with €120,000 this is not particularly decisive in one direction, so in my opinion the repayment subsidy is significantly more important.

Installed a gas boiler.

There is simply no "right house," but in the end, every house is the right one for the specific builder.

those under €10,000 (should be doable),

That is not guaranteed. For some, the financing is so tight that it simply is not doable.

There is simply no "right house," but in the end, every house is the right one for the specific builder. That is not said. For some, the financing is calculated so tightly that it simply is not feasible.

Okay, wow... Yes, if that should really be the case, then the €10,000 could of course already be too much. Independently of the approximately €50 higher repayment rate or financing sum, I consider it economically quite sensible to take advantage of the KfW loan.

We are currently planning a single-family house and originally did not want to build a KFW55 house. In my opinion, the savings potential due to better insulation can be completely forgotten. That might bring about 100-200€ per year.

In the end, however, we have now decided on KFW55 with gas heating + controlled residential ventilation, as we expect additional costs of max. 10,000€. We are, of course, happy to take the 18,000€ subsidy along, even if the KFW interest rate is not so great.