KFW 40 + surcharge for 2 residential units

Hello,

I found the same topic in the search, but from 2016, and the newer answers don’t address the new funding, so I wanted to ask again.
I plan to build a city villa for my parents and sister. (so I am planning it)
Now the standard offer from Dennert is with a heat pump but without a ventilation system in KFW55.
He says he is reluctant to build with a ventilation system due to cleaning difficulties and resulting poor air quality after a few years.
However, the building envelope already almost meets KFW40 standard. You only find out exactly what needs to be added when the architect calculates everything. But at most, some changes will be made to the roof and floor, with a few more centimeters of insulation added.
Since I am planning a photovoltaic system with storage anyway, it would only be the additional costs for the WRL, probably around 12,000€ plus some small items, so let’s say 15-20,000€.
Since the house has 2 residential units, I get 2x the 30,000€ and the eligible costs for the heating from Bafa will then also amount to around 8,500€, I think. So KFW 40+ and Bafa are 60,000€ + 8,500€ grant + KFW 431, so let's just calculate roughly 70,000€.
And KFW 55 would be 36,000€ + 7,000€ + KFW 431, almost 45,000€.
So it’s a difference of 25,000€ and the costs only amount to 15-20,000€, or am I forgetting something here?

Do I see this correctly, that everything argues in favor of it?
Or do you also have the same attitude regarding the WRL as the seller from the company Dennert?

Do I understand correctly that everything speaks in favor?

You see it correctly! But be careful, the subsidies will change starting next year, so you should inform yourself then. I would do it exactly as you wrote.

Hello, I would also like to build KfW40+ since I have to install photovoltaics and it would then be similar to your situation, and the additional costs for better walls/floor slabs/roof and basement insulation would be worth it for the extra funding. I just looked at Dennert's homepage. It said the wall is great and suitable for all KfW classes? Is it now dependent on the ventilation in your case? And is it like in the old post, that they only provide the building envelope and you have to do the rest yourself? Have you already visited a model house or the factory? I am interested in this ETICS. I actually wanted to build monolithically without ETICS, but I explicitly didn’t want to glue Styrofoam or similar to the outside of the wall. At Dennert, it seems to be different, almost like a kind of Ytong block? Did you get any information on that? And how long did you have to wait for the offer, and did you already have plans yourself, and may I ask what price you are looking at with Dennert?

And is it like in the old post, that they only put up the building envelope and you have to do the rest yourself? Have you already looked at a show house or the factory? I would be interested in this ETICS. I actually wanted to build monolithically without ETICS, but I specifically did not want Styrofoam or similar glued to the outside of the wall. With Dennert, it seems to be something different, almost like a kind of Ytong block?

They have their own small house model program, but also wall building materials (probably similar to Liapor), and also a mineral foam ETICS. By the way, have you already seen my email reply from the day before yesterday?