LWW, gas or geothermal operating cost experiences

Friends of mine also built a house that actually corresponds to KfW55, but since they have a gas boiler (and controlled residential ventilation with heat recovery) they only received a KfW70 with a note about the fossil fuel used...

Friends of mine also built a house that actually corresponds to KfW55, but since they have a gas boiler (and controlled residential ventilation with heat recovery), they only received a KfW70 with reference to the fossil fuel used...

The problem does not exist with us. The KFW energy consultant has already approved the house in the planning phase and all KfW applications have been approved.

Friends of mine also built a house that actually corresponds to KfW55, but because they have a gas boiler (and controlled residential ventilation with heat recovery), they only received a KfW70 with a note regarding the fossil fuel used

You can see, this is also political! In the end, politicians decide what is renewable and what is not, and what should be subsidized and what not. This is completely fine, but one should be aware of it. And then weigh their own decision accordingly and not just rely on the KfW xy label.

You can see, this is political too! In the end, politicians decide what is renewable and what is not, and what should be subsidized and what not. That’s totally okay, but you should be aware of it. And then weigh your own decision and not just focus on the KfW xy label.

That’s how it is! Driven purely by politics and lobbyists. At the end of the day, what matters is what it ultimately costs you. Energy certificate or not. Whether A or A+ – who cares??? It’s just window dressing anyway. What’s important is not to be blinded by it and to invest where you can’t change it later: insulation + masonry. You can always replace technology. Although with effort, but it’s possible. You won’t be tearing down the walls anymore.

The Austrians do it better... they even build with 50cm bricks... 38cm is the smallest size there. Here they used to work with 30cm bricks for a long time.

With geothermal energy, there is no visible outdoor unit (just like with gas). If gas is ultimately cheaper to purchase than the air-to-water heat pump, I would choose gas.

There are also air-to-water heat pumps without an outdoor unit. Stiebel Eltron LWZ305, for example....

We were also faced with the decision and chose an air-to-water heat pump.

A gas condensing boiler was completely ruled out for us. Our developer would have only installed one with a high flow temperature, which would have made the underfloor heating unsuitable for heat pumps.

Since we have to finance our project, we decided on the heat pump with the lower initial cost, namely the air-to-water heat pump.

According to our calculations, the savings in consumption costs with the geothermal heat pump would not be sufficient to recoup the additional costs.