Single-family house - 18,000 kWh in two years - what could be the problem?

erzapp How do you come up with these numbers?

19000 in 2 years 9500k/2 residential units that is 4500kw including heating per household. Without knowing the exact m2, that’s okay.


Regarding your problem, you first have to separate the 2 apartments, an electrician does that, then he applies for the 2nd meter.

For the heat pump, you need a heat quantity meter at the transfer point to the granny flat for billing heating and hot water.

We do not have a second meter from the energy supplier, but our own calibrated meter to read the electricity for the granny flat.
But as I said, electricity for hot water, cooling, ventilation, and heating is not included there.

We have a heat meter in the return flow of the heating of the granny flat.
Since the tenants have moved in, the meter has risen from 7.237 MWh to 13.090 MWh. But no heat meter was installed for hot water. That means the tenant has used 5.853 MWh for his heating. But what if cooling is done via the same route? What does the heat meter do then?

I also have a heat meter in the heat pump:
Heating, compressor only: 28642 kWh
HW, compressor only: 7045 kWh
Heat including internal auxiliary heating: 45637 kWh
HW, including internal auxiliary heating: 7873 kWh
BF1: 18.4 l/min

But these are probably values since commissioning in 2017.

Oh guys, you have no idea how much this annoys me. I’ll be glad when everything has settled in/at the house and I know how everything works and is supposed to run.

I spoke with my former property developer some time ago and he said he would charge it like this:

Nutzstrom: The granny flat has its own meter
Heizung/Kühlung/Warmwasser: Electricity costs of the heat pump divided by number of people (4 in the house / 3 in the granny flat = 43% of the costs to the granny flat) or living area (approx. 125m² / 75m² = 38% of the costs to the granny flat).
Kaltwasser: Costs for water/sewage allocated by number of people

Could it be done like that?
It wouldn’t be precise, but simple.

Typical problem, the heat pump eats an arm. Almost all owners know this.... only proper adjustment helps.

Who helps with the adjustment. My developer initially made different settings than the Nibe service technician. According to the developer, Nibe knows about the pumps, but not about the topic "thermal concrete heating," so various settings by Nibe would not be favorable.

I know I understood it, therefore call an electrician who should separate both apartments and then apply for 2 meters. It was only calculated and that would be okay so far. But 45000k heat quantity is a lot, I have not had that even after 5 years and have 250m2. Okay, let's summarize. How large are the heated areas? How warm is the hot water set? How large is the hot water buffer? How high is the supply temperature?

Have a look at the Heizkostenverordnung. Normally, heating costs must be read off. However, I'm not sure right now if there are exception rules for [Einliegerwohnung]. You can settle all other additional costs however you want (area, persons, consumption...).

I spoke with my former builder some time ago and he said he would charge it like this:

Electricity for general use: The granny flat has its own meter Heating/Cooling/Hot water: Electricity costs of the heat pump divided by the number of people (4 in the main house / 3 in the granny flat = 43% of the costs to the granny flat) or by living area (approx. 125m² / 75m² = 38% of the costs for the granny flat). Cold water: Costs for water/sewage allocated per person

Could this be done like that? It wouldn’t be exact, but it would be simple.

We calculated it the same way for the authorities, but that’s my mother-in-law; if she uses a few kWh more, it doesn’t matter, the added value of her supporting us makes it worth it. But with strangers, believe me, they don’t care whether the heating is turned up and the window is open, roughly speaking.