ᐅ Consideration: Efficient heat source OR low heating demand

Hello everyone!

Would the following be a reasonable consideration:
If I invest in geothermal energy (deep drilling or shallow geothermal), I might not necessarily need to build to the KfW-55 standard; KfW-100 might be sufficient because I can access heat energy very efficiently and cost-effectively, so the potential savings from better insulation, etc., are not as significant anymore.
If I invest in KfW-55, I don’t need geothermal energy because my heating demand is already low, and I can use heat sources that tend to be less efficient or more expensive to operate (gas boiler with solar thermal or air-to-water heat pump).
So, in short: either ensure a good heat source or aim for low heating demand. (The savings potential from combining both is rather limited.)

Best regards
jx7

Hello,

jx7 schrieb:

The potential savings when combining both is rather small.)

That always depends on the perspective. For me, both options are beyond payback; therefore, I would always choose the most economically sensible approach.

Regards, Bauexperte

That said: Each of the measures individually may already be economically questionable, and the combination of both measures even more so, because the savings potential becomes even smaller and the payback period therefore even less certain. But of course: it always depends on the specific case (climate, house size, heating habits, soil conditions, roof orientation, etc.).

Hello,

jx7 schrieb:
To put it this way: Each measure on its own might already be economically questionable, and the combination of both even more so, because the potential savings become even smaller and the payback period even less certain. But of course, it always depends on the specific case (climate, house size, heating habits, soil conditions, roof orientation, etc.)

It must be some kind of male thing...

Looking at it objectively, building a house never really pays off. The first few years are calm; however, you still need to set aside funds for the worst-case scenario; the garden is being cultivated. Starting at around 12 years, you begin to replace the then outdated technology, such as the flow temperature system, interior doors, tiles, carpets, etc. What no young builder can imagine becomes increasingly realistic over time: that is, when the children have left the nest, the home suddenly feels large and empty. It is not uncommon to then start over from scratch, and the house-building project begins anew.

So, if you are looking for payback, skip building a house and remain a tenant. It also protects your peace of mind, and the place can be changed more easily if unpleasant neighbors spoil the view.

Best regards, Bauexperte

Well, building expert – you are certainly right about the house construction itself – but I do understand jx7’s question.
The leap from KfW 70 to a true passive house, for example, is financially huge – while the heating/hot water system plays a rather minor role in that. Perhaps a KfW 70 house with a more expensive ground-source heat pump? Significantly lower investment in the building and a bit more for the heat generator? And then calculated over the years… – taking into account factors such as climate zone, house size, occupants, etc.…

Hello,

Cascada schrieb:

... but I do understand jx7's question ....

With my answer, I wanted to make clear that there can be no return on investment in new construction. How much “extra” beyond what is “necessary” / “economical” or how much can be attributed to a “green conscience” is something everyone must decide for themselves based on their preferences and budget 😉

Regards, Bauexperte