Is it reasonable to calculate construction costs by cubic meter in a gallery?

Hello, we have now had our house drawn and calculated by the architect. For the first cost estimate, he used the volume. The house with a basement on a slope has around 855 m3. However, we do not really have a "real" upper floor since over half of the ground floor has a gallery (above the entrance, guest WC, and office), and the space above the living and kitchen area is open up to the roof. We are now planning a roof between 20 and 30°. Now my question is, are the classic m3 costs (assumed by us to be 320€/m3) reasonable. The empty space above the living room alone costs us a fortune. And if we had inserted a ceiling there and had rooms on the upper floor, the volume would be the same but the price probably not the same... The same applies to the roof; the additional (dead) volume created by the 30° roof cannot be calculated at the same m3 price as the rest, can it? Otherwise, I would choose a flat roof. Are there possibly different m3 prices for these "empty" volumes? Thanks!!

That’s why it is called an estimate.

You might save money on the suspended ceiling. However, you will need, for example, scaffolding inside the house if you want plaster and paint on the walls at the height of your gallery, which is 4 or 5 meters high. Costs will arise due to a construction method that do not occur with another, and vice versa.

Using different cost rates won’t help you much. That is comparing apples to oranges.

Have your architect create a detailed cost plan, then you will know better. Then have the house planned without the gallery and estimate the detailed costs again. That way you have a somewhat comparable approach.

Hello and thanks for the answer. Still, another question. Why are the construction costs (as I have heard more often recently and as it seems to me) about 30% higher in Bavaria than in the rest of the country? So we live in Lower Franconia, no idea if that applies there as well, but I generally don’t understand if that is the case. It makes sense to me that the hourly wages here are a bit higher (but not higher than in Hesse or Baden-Württemberg either), but 30% of the construction costs? Or are the material costs also that much higher here? Then I could just buy a prefabricated house from the north?

Thanks if someone can enlighten me

Hello,

Just the empty space above the living room costs us a fortune.

So you think that air spaces don't cost money?

And if we had installed a ceiling there and rooms on the upper floor, the volume would be the same but the price probably wouldn't be the same...

No, the price would have stayed the same; the volume doesn't change.

The same applies to the roof, I can't calculate the additional (dead) volume with the 30° roof at the same m3 price as the rest, can I? Otherwise I'd take a flat roof.

A flat roof will be more expensive for you

Rhenish regards

Good evening,

So I could buy a prefabricated house from the North?

You can. Then transport, labor, and accommodation costs would be added, and you would be back to where you started, which you will pay anyway if you hire a regional provider.

The price difference in Germany results from the varying wage, living, and housing costs. Material costs also depend on these factors.

Rhenish greetings

BaWü is not cheaper than Bavaria either. But by now, every German citizen (especially us "Southern statesmen") should know that costs (and also salaries) are higher in the South. I can't say much about the airspace. Just this much: Those I know, with a house with airspace, also have good money.