Classify heating costs single-family house 200m2

Hello!

As part of our considerations to realize our construction project for a single-family house in the next 1-2 years, my parents-in-law have offered us to take over (buy) their house.

My wife and I have already weighed the various advantages and disadvantages quite well. However, what worries me a bit are the heating costs, which I can't really assess, as I simply lack comparison options.

Maybe you can help me with that.

Here are the facts:

Single-family house built in 1985 in solid construction with 200 m2 of living space spread over 2 floors.
Exterior walls: 24 cm Poroton + 4 cm insulation (no further details noted in the building application) + 11.5 cm clinker brick.
Insulation in the roof: glass wool + vapor barrier (no further details).

The house has a full basement (not heated) with 30 cm concrete exterior walls.

Now I have obtained the gas bills from the past years. On average, the consumption over the last 10 years was 40,650 kWh. Installed is a gas-fired central heating system (about 15 years old). Hot water is included.

The offer my parents-in-law made to us is really tempting. There wouldn't need to be much renovation at first, as the house is in impeccable condition (my wife and I currently live in the house together with my parents-in-law).

What do you think, how should the consumption be assessed?

Best regards

A more precise assessment than the present billing you will certainly not get in the forum.

Hi,
so 40,000 KWh is really quite a lot.
My house (187 sqm living space) was built in 1982, heating system renewed in 2008. Gas condensing boiler with solar support for hot water and heating.
Consumption is around 20,000 KWh.........
Regards

You probably won't get a more precise assessment than the existing billing in the forum.

Sure, I'm also interested in comparison values...

@E.Curb

How are the exterior walls of your house constructed?

Because with comparable living space and year of construction, a consumption twice as high is really intense. What also makes me skeptical is the fact that the consumption has not changed since my wife and I have been living on the first floor. My wife had already lived on the first floor before (her parents live on the ground floor), but not all rooms were finished and heated. Shouldn't the consumption have increased from that point onward?

And does anyone possibly have an idea where the high consumption comes from, or who could be commissioned to investigate the cause?

Best regards

So basically, buildings cannot be compared solely based on consumption. I just wanted to give you a rough point of reference. Contact an energy consultant. They should be able to investigate the causes.

a) she is currently heating for two households, including hot water. b) the desired room temperature makes quite a difference. Maybe heat less sometimes.