Explanation of the energy certificate for new construction Kfw70 multi-family house desired.

Hello. I want to buy a new apartment in a multi-family house (5 units). The new building was completed in summer 2016. Since this building is according to Kfw70 and there are no reference points regarding energy consumption yet, I have received the energy certificate. The heating system is a pellet heating system with solar support.

Regarding the energy certificate for residential buildings according to §§16 Energy Saving Ordinance
- detached multi-family house
Building usable area 900m2 (is this the area that must be used to calculate the pellet quantity? or the living area?)
Volume 2800m3
Envelope area 1300m2

Final energy demand? 55 kwh
Primary energy demand 17 kwh
Solar energy 19%
Biomass 81%
Actual value annual primary energy demand 17 kwh
Energy saving ordinance new building 52 kwh (-15%, -30%, -50%)

Question:
So the building is operated with a pellet heating system and a solar collector system on the roof (for heating support and hot water via a buffer tank).
The apartments have underfloor heating and window ventilation with bathroom ventilation.
The current owners told me that the pellet consumption is extremely high!
(December approx. 1.7 tons with no severe winter so far, Nov. 1.5 tons, Oct. 1 ton.)
More information about pellet consumption could apparently not yet be collected.
If I extrapolate the pellet consumption, I come to a pellet consumption of approx. 14 tons!

What would be the actual calculated pellet consumption for this building based on the energy certificate approximately?
54 kwh/m2 with a building usable area of 900 m2 = 48600 kwh.
5 kwh should be approx. 1 kg pellets. That would be 9700 tons.
So much less than in reality!

Or how can one calculate the approximate pellet consumption based on the above data?

Thank you very much

And daily the groundhog greets you ;-) What do you intend to achieve here? But nice that you slightly change your story with each attempt, at least it stays interesting.

The story again. But you realize yourself that you have a flaw in your reasoning, right?

How the heck do you come up with 14t?

The average consumption was 1.4t over three heating months. For 6 heating months I come to 8.4t, and thus even less than you would have expected.

By the way, decide whether you have already bought the apartment or still want to buy it.

Otherwise, everything has been said.

Once again the story. But you realize yourself that you have a logical error, don’t you?

How the hell do you come up with 14t?

The average consumption over three heating months was 1.4t. For 6 heating months, I come to 8.4t and thus even less than you would have expected.

By the way, decide whether you have already bought the apartment or still want to buy it.

Otherwise, everything has been said.

Hello. Of course, I did not take December consumption x12! I calculated realistically. In September, according to residents, 1 ton was consumed! In July and August 500kg. In total, about 14 tons. The heating runs all year round! Although there are collectors on the roof for hot water... (That also confused me)...

Therefore, I would be interested (I have not bought the apartment yet! A colleague bought one here!) what the building should consume according to the energy certificate (of course only approx.). I know that a new building (residual moisture) and incorrect ventilation/heating can change the value.

But it should be possible to determine an approximate consumption value....

Hello,

...In Summe also ca. 14 To.

So there is a number after all ;-)

..
Therefore, I would be interested.... what the building should consume according to the energy certificate (of course only approx.)

Such a thing does not exist. Just read the fine print in the certificate.

...But it should be possible to determine an approximate consumption value....

Based on data from energy certificates, no reliable real consumption can be diagnosed. There are other procedures and methods for this.
The fact that this does not work was already shown by the experiment above with the 9.7 t ;-)

Best regards