Is Kfw100 sufficient?

Hello,

we are currently visiting various construction companies. Everything from Kfw100 to Kfw55 is being offered. Regarding the topic of building services engineering, whether heat pump or gas condensing boiler with solar technology for hot water, we are still undecided ourselves.

Now we are asking ourselves whether Kfw100 would not basically be sufficient? With KfW75, you would receive an interest advantage in the funding, but I am not sure about that either, or I have not yet calculated whether this interest advantage is worthwhile in relation to the expenses for a KfW75 house at all.

Is there such a big difference in terms of energy balance and costs between KfW100 and KfW75 that the additional costs are worth it?

Kfw100 would be 100%, Kfw70 consequently 70%. Savings potential: 30% The 100% shift from 2016 (?) due to the new Energy Saving Ordinance 2014, then you would have with a Kfw100 house (Energy Saving Ordinance 2009) a house that consumes more than 100% :( Oh God, who is supposed to understand that? :eek:

In comparison to the respective reference building :)

Well, I already understood the part about the percentages regarding the reference house. I just wonder how the investment costs of a KfW75 house compare to the consumption of a standard KfW100 house. So does one actually save enough that the costs pay off after a certain period?

KfW 70 is supposed to be profitable, KfW 50 is not.

Good evening,

Well, I had already understood the percentages regarding the reference house. I just wonder how the investment costs of a KfW75 house relate to the consumption of a standard KfW100 house. So, do you actually save enough that the costs pay off after a certain time?

"The energy demand of a KfW 70 efficiency house is lower than that of a single-family house built purely according to the Energy Saving Ordinance. Thus, a KfW efficiency house 70 requires only 70 percent of the energy of the reference building = 100% as defined in the Energy Saving Ordinance. The smaller the number (KfW 55, 40, or PH), the more energy is saved; the higher the funding from KfW." This is the explanation, in excerpts, from the KfW website.

The step from the reference building to KfW 70 is not that expensive; most providers already include underfloor heating as standard today. What is usually missing then is a heat pump; at least a ventilation system with heat recovery, if a gas/condensing boiler is to be installed. Additional cost for a ventilation system with heat recovery is about EUR 8-9 thousand.

Now you can calculate for yourself, based on rising energy costs, when a KfW 70 efficiency house pays off ;)

Rhenish greetings