Build a single-family house as KfW55 or Efficiency House 70?

Hello everyone,

we hope you can help us a bit. We have bought a plot of land, the notarization appointment has already taken place and we are now waiting for the payment deadline. We are already enquiring in parallel with [Massivhausfirmen] which we have shortlisted and already have 2 offers, the third appointment was today.

For us it was clear so far that we are building a KFW 55 single-family house (approx. 125 sqm living space ground floor + upper floor) with a full basement (30 sqm basement possibly as living space with underfloor heating), photovoltaic system, heat pump and underfloor heating with individual room control.

Today we were asked for the first time why we actually want to build KfW55. An efficiency house 70 would be about €20,000 - €30,000 cheaper and in addition about €15,000 for the photovoltaic system. Until we have recouped the additional costs for fulfilling KfW 55 standard with photovoltaic system by saving energy costs, the house would be a good 15-20 years old. The subsidies except for the €5,000 from the KfW are also not as good as they used to be and rather unprofitable.

We have already received an offer from 2 construction companies, here the question why not KfW70 never came up.

We are now really a bit confused and would like to exchange some thoughts about this.

Many thanks in advance.

The general contractors like to charge a lot so they can call their house KFW55. In practice, it costs hardly more today to build KFW55 compared to the Energy Saving Ordinance. If you then end up with a "KFW57" it doesn't matter anyway because the subsidy is not worth it.

An Effizienzhaus 70 would be about €20,000 - €30,000 cheaper [...] We have already received an offer from 2 construction companies, and the question of why not KfW70 never came up.

The question cannot arise because KfW70 is outdated by the Energy Saving Ordinance 2016 and is therefore no longer subsidized. In this respect, I also find it difficult to imagine what an "EffizienzHaus 70" is supposed to be: from the term, I would expect it to mean a KfW70 house (at a time when the Energy Saving Ordinance 2014 was not yet mandatory).

Well, you can ask a lot of questions: why a basement, that is, inferior living space, isn't it better above ground?!
Why a shower in the guest toilet, why no shower in the guest toilet?
Therefore, nothing has to be wrong with that!

By the time we had worked the additional costs for the fulfillment of KfW 55 standard with photovoltaic system back in through savings on energy costs, the house would be a good 15-20 years old.

Look, the skeptic himself named a reason. You invest money in the house and have an ROI of 12 years. And after 25 years, you have a clear profit. There are worse decisions.
As for subsidies: take them if they align with the goal. But don’t lose sight of the goal because of the subsidy.

As far as funding is concerned: take it along if it lies on the way to the goal. But don’t lose sight of the goal for the sake of funding.

Which once again reinforces the saying that the devil always sh*ts on the biggest pile, because it ultimately means that funding is a nice extra for those who don't need it - which in my opinion puts the purpose of funding aimed at private individuals (even below the social insurance threshold) into question.