Lowering the KfW level - impact on loan amount?

Hello dear community,

I have been pondering for a few days about a problem with our KfW funding that I would like to bring to you:

We originally started our house renovation with the intention of submitting individual applications through Bafa, which has already been done for the geothermal drilling. However, before the actual start of construction, interest rates skyrocketed, so we decided to opt for KfW-55 funding instead. At that time, our energy consultant advised us to choose the EE supplement and drop the Bafa application. Although the geothermal drilling would then no longer be retroactively eligible for funding, the higher subsidy amount and the higher loan amount from the EE supplement would compensate for that. The only downside was that since 2023, a ventilation system with heat recovery is mandatory in all EE levels, and we actually do not want a ventilation system (my wife works in filter manufacturing and can only confirm all the disadvantages circulating on the internet). We then asked the energy consultant what such a system would cost, and he told us we should expect around 10,000 euros. After a brief rough calculation, we decided that the EE program was still worthwhile and decided to only use the ventilation system when needed. So we finally applied for the KfW-55 EE (the Bafa application has not yet been withdrawn, but that's not urgent as long as we don't apply for disbursement), received the funding grant, and started. Now that we have reached the point where the ventilation system should be installed, we had to find after comparing several offers that it will rather cost around 20,000 euros. Spending that much money on something we do not even want makes us think, and moreover, our cost-benefit calculation now looks quite different. The question arises whether we should forgo the EE level after all and have the heating (including geothermal drilling) funded through Bafa as originally planned.

I have already informed myself: a downgrade to a lower KfW level is possible even after the start of the measures. What I am wondering, however, is how this affects the approved funding sum, as we would then have a lower entitlement.

And one more question: According to the energy consultant, the ventilation system is necessary anyway because otherwise, we would have to deal with mold problems. However, we have two acquaintances who built a KfW-55 house without EE and also without a ventilation system and still have no problems.

According to the energy consultant, the ventilation system is necessary anyway, because otherwise we would have to deal with mold problems.

Well, you need a ventilation concept, and ventilating is comfortable and energy-saving with a ventilation system.

However, we know two people who built a KfW-55 house, but without EE and also without a ventilation system, and they still have no problems.

How do they ventilate then? Manually? Ventilating three times a day means hard work and half an hour of effort every day. In winter, that means letting energy out through the windows. That’s why KfW houses require the ventilation system.

all the disadvantages circulating on the internet,

What would those be?

my wife works in filter manufacturing

Is it the case that if you work in manufacturing, you know what it does to you? I’m just looking for a comparison. If your wife worked at Berentzen or Holsten, would she then know what my liver looks like? I can’t imagine that! Anyway: to your question. I don’t know exactly. But I’ve heard that you simply don’t get anything if you haven’t achieved what you applied for.

I don't know exactly. But I heard once that you get nothing if you haven't achieved what you applied for.

Thank you anyway for your effort!

Thanks anyway for your effort!

It would be nice if you could answer my questions :) Maybe then you will see things more clearly…

With regard to your questions, I already have a clear view. Therefore, I did not ask those but rather the ones in the topic of this thread, from which I would prefer not to digress. Maybe someone else is familiar with the funding modalities.

That's why I didn't ask these either,

But you do realize that here in the forum, both questions and answers are allowed equally, regardless of which user, so that a lively exchange ultimately leads to the answer?

And if you apparently know more, and someone asks you about it, then you should also have the decency to explain it.

Again: I and certainly many others here would like to know which prejudices exist regarding the ventilation system or which of them are true, as far as filter manufacturers or their employees can assess.