Determine energy performance certificate for KFW-40 or KFW-55 house

Hello dear forum,

is it possible to determine with the help of an energy certificate whether it is a KFW-40 or KFW 55 house?

From the line:

Primary energy demand
Actual value 23.5 kWh/(sqm a) and requirement value 68.6 kWh/(sqm a)

I would have thought, since 23.5/68.8 = 0.34, that it is a KFW-40 house (actually even a KFW-34 house), or am I wrong?

Energy certificate:


Best regards
Leisinger

We have a kfw70 but the energy demand is lower than that of a KfW 55.

Basically, you can assume if,

ventilation system and heat pump.

In addition, an energy consultant is necessary who provides proof of the thermal bridge.

The blowdoor test must be below 1.

But why do you want to know it so precisely, the values on the energy certificate are decisive for the calculation of heating costs.

Thank you very much for your reply, for the classification of the building and for comparison it is interesting whether it is a KFW-40 house or not.

Best regards
Leisinger

For KFW-40, in my opinion, the transmission heat loss is too high at 62% (= 0.23 / 0.37), but it is sufficient for KFW-55. (This is what the "Anlage zum Merkblatt Energieeffizient Bauen" of KFW tells me)

mfg

Hello,

all right, thank you. So you only have to divide the actual value by the required value - see energy certificate - and then look it up in the "Anlage zum Merkblatt
Energy Efficient Building". We have now installed even better windows, so with H'T/H'T_Ref=0.56 we practically have a KFW 40 house.

Here is the table:
KfW Efficiency House 40 Plus | 40 | 55 | 55 Ref. values
QP in % QP REF 40 | 40 | 55
H’T in % H’T REF 55 | 55 | 70