For what reasons did you build according to KfW 50?

My husband and I are building according to the Building Energy Act, as is well known, because various individual positions to achieve KfW 55 did not appeal to us or we did not understand the construct. We could not clearly follow what were factual arguments and what was ideology.

Prompted by the much-discussed and, in my view, regrettable discontinuation of the subsidies for the affected builders, I am interested in whether you would have built to KfW 55 standards even without subsidies or whether you are now reverting to the Building Energy Act, if still possible.

We built KFW55 (don't know what 50 is?), because according to our consultant we were already so close to the desired standard that basically only perimeter insulation was missing. So we bought perimeter insulation for just under €3000 and spent another €1500 on an energy consultant, but received an €18,000 repayment subsidy in return. You don't need to be a math genius for that. :)

I had to build KFW 55 because the development plan required it here.
At that time, a €5,000 repayment subsidy would have been possible. In return, there were not very attractive terms for the necessary loan of over €100,000 and additional effort for the energy consultant. Therefore, I voluntarily "passed up" the subsidy.

We wanted to build a house with separate trade contracts and external thermal insulation composite system (WDVS) anyway.
To achieve KFW 55, 2 or 4 cm more insulation was needed on the exterior walls, the same on the flat roof and under the floor slab. The windows could only be marginally improved, or the extra cost was very low. For €300, the energy consultant calculated the thermal bridges instead of applying the flat rates. The requirement was to bring the building envelope just under the target value.
So the building envelope could in fact be improved to this level for very little extra cost.

On the system technology side, we were already using a heat pump and controlled residential ventilation; photovoltaics also count positively. Even without photovoltaics, KFW 40 would have been easily achievable. Or KFW 40+, with photovoltaics and if we had added a storage system. End of story.

The energy demand is low due to the system technology and building envelope. We notice this today in heating costs and during construction through saved drilling meters for the geothermal probe.
At that time, it was already being discussed that passive houses would soon become the standard. Then a house built "only" according to the energy saving ordinance would feel like old iron in case of resale. But maybe that’s just a mindset.

Ultimately, the KFW 55 level probably cost about €3,000–4,000 more. I can’t specify exactly.
But that will differ from case to case. Have I already planned a technology package that contributes to that? Am I building monolithically or with WDVS? Is a general contractor ripping me off?

For an extra €15,000, for example, I probably wouldn’t do it without subsidies either.

I find the question rather suboptimally phrased. In any case, I would have built a modern house (~KFW40+) even without the funding. With the grant option, it doesn’t affect the rate anyway, only the term, and whether I pay off over 25 or 22 years doesn’t make much difference.

We would have built according to KfW 55 anyway, because it’s not possible to do worse with timber frame construction. However, due to a few additional measures, we ended up somewhere between Passive House and KfW 40 – this is also no challenge with timber frame construction and only cost a mid four-figure amount.

My husband and I are building according to the Building Energy Act, as various individual items to achieve KfW 55 did not appeal to us or we did not understand the concept. We could not clearly distinguish what were factual arguments and what was ideology.

You belong rather to the avant-garde of those who build KfW 55 but receive no subsidies. Put positively, your building envelope is certainly significantly better than the Building Energy Act.

I renovate according to § 55. Exclusively because of the subsidy, as it is paid through equity and in [EL]. The subsidy compensates for about 30% of the total costs.

The last house was about 60. It turned out that way with our wishes. The subsidy was irrelevant and did not play any role. The house was simply meant to be high-quality. This also had a very positive effect on the sale after moving in. The buyer then also did not look at the efficiency level anymore.