ᐅ Primary energy demand for KfW55 standard

Created on: 3 Jun 2016 12:37
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DragonyxXL
I was a bit puzzled by the primary energy demand in our thermal insulation certificate. Isn’t nearly 50 kWh/m2a (5.0 kWh/ft2 per year) somewhat high for a KfW55 house?

Image of an energy certificate showing a building’s primary and final energy demand
BastianB6 Jun 2016 12:57
The final energy demand definitely seems too high to me! With about KfW55, we have a final energy demand of approximately 10 kWh/m²a.
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DragonyxXL
6 Jun 2016 13:09
So, what do I do now? I can’t exactly go to the structural engineer and tell them their calculations are probably wrong. How can I get to the bottom of this?
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Bauexperte
6 Jun 2016 19:45
DragonyxXL schrieb:
So what do I do now? I hardly can go to the structural engineer and tell him that he probably made a mistake in his calculations.
You can ask him how this discrepancy could be possible.


Bauexperte
Uwe826 Jun 2016 23:48
We narrowly missed 55 with a final energy demand of 15.4.
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DragonyxXL
7 Jun 2016 09:46
Bauexperte schrieb:
You can ask him how this discrepancy is possible?


Bauexperte
That’s exactly what I mean. Discrepancy compared to what? "I heard different figures in a forum," perhaps?
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Bauexperte
7 Jun 2016 09:53
DragonyxXL schrieb:
Well, that’s exactly what I mean. Discrepancy compared to what? "I heard different values in a forum."?

Heavens help...

You wrote: "I was a bit puzzled by the primary energy demand in our energy performance certificate. Isn’t nearly 50 kWh/m²a (15,800 BTU/ft² per year) a bit high for a KfW55 house?" There is a lot to read in forums, but whether it’s always correct is another matter; besides the fact that two houses with different construction types and locations cannot be compared. So, what do you lose by asking your structural engineer exactly this question?

PS: If the calculation is correct, no one will notice—except your structural engineer—even if you blush a little out of embarrassment 😀

Regards, Bauexperte