I need advice on the cost of heating

Hello,


That’s true, moreover it is pointless in the presented combination.


If you assume a "usual" GBR/Solar, that is a bold statement; it decisively depends on the position of the house relative to the sun. Theoretically it is possible, in practice rather very rare. Often additional measures have to be taken.

Rhenish greetings

Of course it’s not always easy, but if you have prioritized thermal insulation and efficiency from the ground up with your construction company/architect, KfW70 should also be achievable with gas/solar. If the roof is positioned unfavorably and hardly gets any sun, that of course is a different matter ;)


Regarding my heating cost estimate, about 3,300 kWh per year are needed for heating + hot water. 63% of the hot water is covered by the solar system. Since I like it to be 24 °C warm and there is also constant ventilation, I assume about 5,000 kWh.
It doesn’t matter whether it’s 400 or 600 euros, an investment of over 30,000 euros can hardly ever pay off, even if the heating costs would fall to 100 euros per year.

Hello,

I just read this ...

KfW55 new building without basement, 1.5 stories, knee wall 70cm, 112sqm living area, 4 floor-to-ceiling, 2 small and 5 normal windows
Roof orientation 30° west/60° south

Exterior wall 36.5cm aerated concrete:
0.2 W/m²K

Filled aerated concrete?

Something like that costs estimated 40,000 euros today and is therefore hardly worthwhile, with about 500 euros heating costs per year :)

What costs EUR 40,000 and how do you arrive at heating costs of €500/year (incl. hot water)?

Rhenish greetings

.... 63% of the hot water is covered by the solar system...

Please install a heat meter in the solar thermal system and later compare the actual yield with the 63%!

best regards

Hello,

I just read this ...


Filled aerated concrete?


What costs TEUR 40 and how do you get heating costs of €500.00/year (incl. hot water)?

Rhine greetings

The aerated concrete has a lambda value of 0.08 w/mK.
Filled? They are continuous blocks without air gaps or insulation wedges inside.


The larger investment I mentioned as an example of 30-40k would be a conversion to a zero-energy house, i.e. with photovoltaics, heat pump.
I have not yet requested a concrete offer for this, as it is currently quite uneconomical.

The estimate of 500,- is based on experience from other builders who chose this house,
and you can also see from the calculated energy demand that it would even be less, which I have not been able to imagine so far. Let it be 1000 euros/year in the worst case, it would still take 30-40 years for the zero-energy conversion to pay off; due to interest and maintenance of the system, I will probably never see the amortization.

...The estimate of 500,- is based on, on the one hand, experience from other builders who have chosen this house,...

A reliable transferability to other BV is impossible!

...Furthermore, one can deduce from the calculated energy requirement,...

Which one? On what basis was it created?

v.g.

...until the zero energy conversion pays off,...

Such terms should be strongly differentiated. These slogans are often used in colorful advertising brochures, of course without any liability or guarantee! ;-) With regard to annual energy balances, such approaches are certainly economically feasible. For self-sufficiency, currently certainly not!

best regards