Which heating is recommended for KfW 55?

Hello,

I would like to revive the older thread here. We also want to move towards KFW 55, but without an air-to-water heat pump and instead with a gas boiler. We have planned a monolithic construction using Poroton T9 with a thickness of 36.5 cm. Passive house windows (triple glazing with U-value 0.83), insulated ground slab/floor ceiling.

We have no interest in [WDVS]... In any case, we do not want any styrofoam in our house.

Now the question is, what else would we need to do to achieve this. The building envelope should be fine, maybe increase the wall thickness to 42.5 cm?

Regards

The building envelope should be fine, maybe still go for a wall thickness of 42.5 cm?

"Believing" won't get you anywhere; ask your energy consultant, he has to calculate. I am sure, with an additional 42.5 and controlled residential ventilation with heat recovery, you don't even have to think about getting anywhere near KfW 55. Rhineland greetings

I forgot, controlled residential ventilation with heat recovery is of course included....

The problem of the missing heat pump probably remains, which, upon closer inspection, is not really ecological due to the high electricity consumption.. nevertheless, the heat pump is subsidized. Of course, we have contact with an energy consultant, the floor plan is currently being revised and since the energy consultant costs money.. we still have to wait for details. But that's why the question here in the forum, who has achieved KFW 55 with what or who knows how to achieve it. Regards

It depends on the heat pump what you mean by high electricity consumption - a brine heat pump, when properly designed, does not have a high consumption. In terms of maintenance costs, it is even cheaper than gas.

We have a converted KFW56 house with KS + 14 cm mineral wool insulation, windows with U-values of 0.6, 24 cm rafter insulation (gable roof 35°), 10 cm perimeter insulation in the basement, no slab insulation and of course a brine heat pump & controlled residential ventilation with heat recovery.

That's just a rough outline...

Yes, certainly a brine heat pump will have lower consumption. However, the opposing costs of about 20,000 euros more investment also hit the budget hard, and as I have learned, one has to expect high maintenance effort and corresponding costs with the heat pump.
Our goal is to achieve the target with little and sensible investment. If this is not possible, then we will have to stick with KfW 70.
Besides the KfW issue, low consumption of our future house is our top priority, which is why the idea of going for KfW 55 also came up when we are already planning a good building envelope.
Best regards