Which type of funding should I choose? KfW, BAFA, tax?

I have already been to an energy consultant (who is employed by my architect). Unfortunately, he wants to know first which type of funding I choose before he calculates anything. When I asked which KfW standard I would reach if I carried out all measures according to the BAFA minimum standard, he said that this would roughly correspond to KfW55. Is that really correct?

Yes, it can be possible if you do everything according to BAFA standards. But it is also very expensive. Although the statement "approximately KfW55" is also dangerous if your loan/grant depends on it. That’s an advantage with the tax situation...

It's hard to judge without details about the house. We are currently renovating a house from 1936, which already has 8cm external insulation WDVS. We are doing the roof new (according to BAFA requirements), new windows (according to BAFA requirements) and insulating the basement ceiling. Still, we don't even come close to KfW55, but end up between 85 and 100.

Friends of ours are starting a renovation soon – they are doing everything completely new and end up at KfW70 or 85 – so also not at 55.

Unfortunately, building year 1961 is on average not known for super solid construction quality.

It's similar for us. If we did everything according to the renovation plan, we would easily calculate below 55 in terms of primary energy demand, but due to transmission energy loss, it still doesn't go beyond a KfW100.

For me as a layman: What would have to be different to achieve KfW55?