Construction costs kfw70 vs. kfw55 vs. kfw40

Thanks already for the first answers. Planned is a multi-family house for rent with 4 apartments of about 80m2 each. Dimensions of the building approximately 20 x 10 m. I had already thought of a high-quality building structure without having dealt with it in detail yet. The background is, as already mentioned above by DragonyxXL, how much effort is required to enable an 'upgrade' from Kfw70 to KFW55. My opinion on the following points: triple glazing: I would do it regardless of the two cases. Construction method: solid, brick Heating: I am independent, gas is available, but I find pellets very charming. Hope the info helps. Thank you very much for your expertise.

Renting and pellets is nonsense (are you constantly in the mood to acquire material?). Especially with renting, the additional costs for Kfw40 are absolutely not worth it. Or do you want ultra elite deluxe rental shacks directly in downtown Munich for nouveau riche people who don’t want to buy but rather rent because of frequent moves?! Better look for extras that make sense for tenants (or for you) like, for example, a ventilation system with which you as a landlord can prevent mold (no incorrect airing). Triple glazing with warm edge is today a "must" for a new reasonably well-insulated house. Only the very cheapest buildings still have double glazing now. No one offered us double glazing anymore.

@ eidnsam

If you want to rent out, build the apartment building as a capital investment, you should focus on what brings you a reliable rental income. A pellet heating system is not part of that, but a ventilation system definitely is.

For an apartment building, a geothermal heat pump is certainly worth considering; KFW 55 will not bring you a cent of additional rent.

If you want to be sure whether your investment will pay off, have a return calculation made.

Rhenish greetings from the road
Construction expert

Follow the post closely. I have similar considerations and would appreciate some cost/benefit numbers. Surely you can't calculate that universally, but any input can bring more understanding here.

The background for us is the target KfW 153 from April 1, 2016.

What is to be built is a KfW Efficiency House 55.

[*]A switch to 40 would mean a 5% repayment grant for 3 residential units, i.e. 15,000 euros
[*]A switch to 40+ would mean a 10% repayment grant for 3 residential units, i.e. 30,000 euros

Different interest rates from April 1 are also conceivable; we have had that in the past.

I don’t want to rush anything here; KfW Efficiency House 55 is set. But I would be somewhat annoyed later if I learned that for 5,000 euros more, for example, we could have achieved 40.

I don’t want to rush anything here, KfW Efficiency House 55 is set. But I would be somewhat annoyed later if I found out that for an additional 5,000 euros we could have achieved, for example, 40.

the subsidy is a lure so that anyone would build these standards at all. otherwise it would never be profitable. going from kfw55 to 40 requires quite a bit and will certainly cost significantly more than your 5000 euros per unit. as the building expert wrote, you should incorporate things into a rental property that provide the landlord with security (e.g. ventilation system) or increase the rent through better equipment (terrace/balcony // roller shutters etc...). whether the tenants pay 10 euros more per month for heating or not is completely irrelevant and does not justify the rent increase to cover the additional costs.

I also think that the disorientation from kfw 55 to kfw40 is significant. I am particularly interested in how big the leap is from 'without KfW funding' (or kfw70 standard, which will no longer be supported from 1.4.) to kfw55.
For my intended property, that would be 4x5,000€ repayment grants and in addition the possibility to finance 400,000€ at 0.75% (and thus half a percent better than at the bank).
Financially, I can roughly calculate it myself, but what do I have to invest more in terms of technology and building fabric, what makes sense, and what will it cost me?