2 offers for a single-family house in MV, large difference, is the offer plausible?

Only the ceiling is just cheaper, the roof insulated as well is simply the best standard

I consider that unnecessary. Either you insulate the floor ceiling and leave the attic cold. Or you insulate the roof, but then also use the attic within the thermal envelope (storage, hobby).

In both variants, you have the choice of insulation thickness or the resulting U-value and will probably always achieve a better price-performance ratio than with insulation on the ceiling and additionally under the roof (multiple work steps, etc.).

I consider that unnecessary. Either you insulate the ceiling of the top floor and leave the attic cold. Or you insulate the roof, but then also use the attic within the thermal envelope (storage, hobbies).

I agree. Here, the size of the attic, the roof pitch, and the direction the staircase runs clearly argue against using the attic for more than storing a box of Christmas baubles and a box with the old Carrera slot car track - and thus clearly in favor of insulating the ceiling of the top floor and that's that. Unless you're planning a hemp greenhouse up there, I wouldn't know who would benefit from insulating the sloped roof in this case - even the cat won’t hide there. It will be purely an aesthetic roof and can be, in Siberia, completely outside the thermal envelope.

All right. Understood: point 4 is checked off. We can continue with the other points.

All right. Understood: Point 4 is checked off. We can continue with the other points

well, you’re not really following the idea of having a professional check your documents. have you ever visited reference customers for your Fiat and Audi?

well, you're not taking the idea of having a professional check your documents to heart.

have you ever visited reference customers of your fiat and Audi?

How often am I supposed to go to the professional? I only go to them when it’s time to sign. Until then, a thousand things will still be changed.

How do you now come to the assumption about the Fiat and Audi? Don’t you recognize qualitative differences in the two offers?

How often should I go to the professional? I only go to him when it’s time to sign. Until then, a thousand things will still be changed.

...?

But that doesn’t mean you should get 1000 offers.

Offers must go hand in hand with a good gut feeling and feasibility. Then there shouldn’t be that many left who make concrete offers.

The Sisyphean task of checking a construction service description for errors or additional costs cannot be provided by a forum.

And honestly: maybe you should give a professional a chance at your side if you yourself have little knowledge about it.