Is KFW300 possible without QNG seal?

Hello everyone,

I am not quite clear about the KfW homepage.
Our house provider achieves KfW40 without QNG. Can I then use the KFW300 funding program with that? Or is the QNG seal absolutely necessary?

Regards

Philipp

I am not quite clear about the KfW homepage.

Reading helps. Both options are possible. The loan amount is different in each case.

Well, kfw 40 is not enough for 300. The crux is the CO2 emissions. So 40+. You might manage that with a lot of calculation tricks, possibly with a geothermal heat pump, or a completely pimped local heating system.

But your house builder should know all this.

It can be built with or without [QNG], although with [QNG] it is not worth it at all. Most people do it without [QNG] and [KFW 40] with [LCA]. It is also quite easy to achieve with a few small improvements to the roof and base plate. Nothing too wild. We are currently right in the middle of complete solid construction.

Most people do without QNG and KFW 40 with LCA. It is also quite easily achievable with a few small improvements to the roof and floor slab. Nothing to worry about. We are currently right in the middle of solid construction.

Can you provide a bit more detail regarding your solid construction with KFN40 (especially wall structure)?

We have just had two initial talks with local architects, and in both cases it was made very clear that solid construction with KFN40 is practically not built in our area. The additional costs compared to the Building Energy Act would be so massive that in both cases (and these were not small architectural firms) there is practically no experience due to lack of demand.

Can you give some more details regarding your solid construction with KFN40 (especially wall structure)?

What specific questions do you have? KfW40 is not a problem. You just have to insulate properly, install suitable windows/doors, and use heat pumps/controlled residential ventilation/photovoltaics.

We just had two initial talks with local architects, and in both cases it was clearly stated that solid construction with KFN40 is practically not built in our area. The additional costs compared to the Building Energy Act would be so massive that in both cases (and these were not small architectural firms) there is practically no experience due to lack of demand.

Correct. It’s really not worth it. Either with QNG and subsidies or just as it fits. Because in the end, the energy consumption of both variants (55 and 40) is very close to each other. If you heat a typical single-family house 55 with 600€ per year and a single-family house 40 needs only 450€, it takes more than a lifetime to recoup maybe 10-15k extra costs. In doubt, you build with ETICS and then get annoyed about too thick walls. Or you switch to resol insulation for a thin ETICS structure, where the insulation material alone easily exceeds 100€ each.

P.S. I implemented a resol wall structure myself during renovation. I heat 120 sqm living space (formally KfW 55, but better insulated walls) with 350€ including hot water per year. So why should I try to achieve a 40 house? Better take care of external planning of your heating system, because that’s where much more is going on than in the wall structure between 40 and 55.