New underfloor heating instead of radiators and controlled residential ventilation; yes or no?

We are currently planning the construction of a new single-family house with 134 sqm of floor space in Lower Saxony through a developer. The house is to have KfW 70 standard. We are now considering installing underfloor heating instead of regular radiators. According to the developer, the additional cost would be about €8000. Is it worth it? What about rooms like, for example, the bedroom? Usually, we have the window open at night there. Furthermore, we are considering installing a controlled residential ventilation system. With the ventilation, we could achieve standard 55 and thus have further funding opportunities. The ventilation would cost us about €4000 after subsidies. Is it all worthwhile??

Hello,

I'll put it this way, both alternatives are about comfort.

I know underfloor heating from my parents' house and I already miss it in my current apartment. That's why it was clear to me that if we build, we will get underfloor heating. They can be controlled per room.

Regarding the [Kontrollierte-Wohnraumlüftung]: We also chose the [Kontrollierte-Wohnraumlüftung] because we don't have the time or desire to ventilate adequately 3 - 5 times a day.

Whether this comfort is worth an additional €12,000 to you, you have to decide.

Building a house with radiators nowadays? Why would anyone do that? Do you have money to throw away?

A controlled residential ventilation system for just 4K extra then definitely without batting an eye... but first clarify whether it is a central system and not just a couple of fans in the walls... otherwise, it would be rubbish..

Nowadays, building a house with radiators? Why would anyone do that? Do you have money to burn?

A controlled residential ventilation system for just a 4K surcharge, then definitely without batting an eye... but first clarify whether it's a central system and not just a couple of fans in the walls... that would be nonsense..

The system costs €9500. But I have already deducted the two subsidies. €2500 repayment grant from the KfW and €2000 is given by the city as a grant for a KFW 55

Yes, I already understand that the money comes from the funding... you don't have to explain that again... I just meant that I wouldn't even think twice about the price...

For KfW55 certification and subsidy, you will certainly need appropriate construction supervision and documentation - from pretty much the very beginning. This is probably now required by the KfW due to too much misuse in the past. Please do not overlook these costs and clarify them in time.