Build a multi-family house according to the Energy Saving Ordinance or KFW55?

Let's say kfw 55 increases your construction costs by 15%. That is 150 thousand on a million. That is never worth it, even if they give you 15%.

Without being an expert, I think that it is anyway hard to quantify. KFW is primarily a clever way of calculating.

Sorry, that simply can't be said in general. Maybe the insulation is already sufficient, maybe not. Maybe only for the two units on the upper floor. A heat pump can be cheaper than gas with [ST]. So either leave it as it is or plan and calculate.

Let's say kfw 55 increases your construction cost by 15%. That’s 150k on one million. That will never pay off, even if they give you 15%.

You are absolutely right. I had roughly calculated about a 10% surcharge. Even at 10%, it wasn’t attractive enough.
I will stick with my Energy Saving Ordinance BV.

We will discuss it again with the energy consultant, calculate, and have offers made. Then I will know more, but intuitively it won’t be worth it..

Without being an expert, I think it's hard to quantify anyway. KFW is primarily a clever accounting.

What do you mean by accounting??

The ground floor and the upper floor each consist of 2x2 apartments, and at the top is then my penthouse apartment...
So not to take advantage of the subsidies..?

Why do you consider a heterogeneous object homogeneous?
I would consider that separately for the bungalow of the four-family rental house on which it stands.