ᐅ Electricity Costs for Air Heat Exchangers?

Fourteen months ago, we took possession of our prefabricated house from the company Streif Haus after a construction period of nine months (including planning, the total was even 17 months). However, after one year, we noticed that the house consumes an unusually high amount of electricity (about 10,500 kWh in one year). Our photovoltaic system, including a battery storage unit, produced approximately 2,600 kWh, so nearly 8,000 kWh still had to be drawn from the grid. Previously, my wife, our 21-year-old daughter, and I lived in an almost equally large rental apartment and consumed about 2,500 kWh of electricity annually.

Our new house is equipped with the most modern and energy-efficient appliances (at least A+ rated), and all lighting is LED-based. In winter, we use a wood stove for heating, and in summer, we prepare food on the gas grill almost daily. Since we also do not heat excessively (always only at the lowest or second-lowest setting for the underfloor heating) and the ventilation system runs only occasionally and then only on the lowest level, we cannot understand the unusually high consumption.

Moreover, we had Streif Haus build us a KfW-40 Plus house, which is supposed to be especially energy-efficient. The company is not cooperative at all and does not take responsibility, instead placing the blame on our consumption, which, as mentioned, should actually be lower than in our previous rental apartment.

My question is: What is the typical electricity consumption in a KfW-40 Plus house with a photovoltaic system and battery storage for the ventilation system and the heat recovery unit?

Thank you in advance for your answers.
Achim D., 85395 Attenkirchen.

What kind of heating system do you have? How large is your house? Normally, it should be more in the range of 3,000 to 5,000 kWh. The pink forum offers good help with this.

Is that the total house electricity consumption? So, including heating?

If yes, then the heating might be incorrectly set, just a guess.

So, you don’t have underfloor heating but a real air-to-air heat pump?
Since when are air-to-air heat pumps economical? I’ve heard they should only be installed in passive houses.

What type of heating system do you have specifically? You mention a "air heat exchanger," which sounds like an air-to-air heat pump, but at the same time you have underfloor heating, so is it an air-to-water heat pump?

Regardless: a reasonably modern heating system records its annual energy consumption and displays it on the control panel.

House electricity usage should be no more than 5,000 kWh per year, and heating/hot water electricity consumption around 2,000 kWh per year. Otherwise, something is not working correctly.

Heating the rooms too little usually makes things worse with underfloor heating, as the energy consumption ends up much higher than maintaining a comfortable temperature constantly. In this case, Streif Haus may not be entirely wrong.

If he writes about underfloor heating, it cannot be an air-to-air system.