Living space enlargement - Evaluation of an offer for an extension

Hello everyone,
I hope someone here might be able to help me.
We would like to build a timber frame extension (13.90 m long and 3 m deep) onto our basemented old building. The basement protrudes about 80 cm above the surface (see attached pictures).
The extension (without basement) would have to be leveled with the ground level of the old building.
On the required new foundation, a flat-roofed timber frame building will then be constructed.
The area is easily accessible for trucks and there is enough space for equipment/crane, etc.
Now my question: I already have an offer from a construction company. It includes the following items:

Construction site setup (incl. portable toilet): 5,600 EUR
Earthworks building: 6,800 EUR
Drainage building plot: 1,600 EUR
Reinforced concrete works: 16,200 EUR
Sealing works: 1,400 EUR
(an 8 m basement outer wall shall be insulated and sealed)
Hourly wage works: 17,800 EUR

This results in a total amount of 49,400 EUR (net) = 58,786 EUR (gross).

No wooden walls or other fittings are included yet!
The price seems very high to me.
Is that normal?

Assuming that the finishing costs account for 60% of the total amount, we would end up at about 150,000 EUR for approximately 40 m2 extension!

I would be very grateful for any experience, preferably professional answers.

Since prices are very individual and also region-dependent, a second offer is necessary for you to assess the first one.
There isn’t much more advice to give.

Nice house!

The offer is understandable to me and the price is OK, provided that the process and quality are right afterwards. I would accept the offer from a well-reputed local owner-operated company with their own employees and a good tone on the construction site (this can be researched). Otherwise, I would continue searching. The price is important. The building partner is important too. The best building partner is rarely available at the lowest price. It is a matter of balance.

The offer is understandable to me and the price is OK, provided that the process and quality are right afterwards. From a well-reputed local owner-operated company with its own employees and a good atmosphere on the construction site (can be researched), I would accept the offer. Otherwise, I would keep looking. The price is important. The construction partner too. The best construction partner is rarely available at the lowest price. A question of balance.

Thank you very much for this honest assessment. What do you think, what additional costs would we incur besides this offer for the timber frame construction and the finishing work?

I would also get an offer and do a rough cross-check. There are huge differences in execution - how many rooms, what kind of electrical installation, what kind of wall finish, what structure, what facade.... I don't see myself able to put a price tag on it. I would roughly set aside 100k for it and be happy if it's less, but what does that really say.

Hello, regarding practical experience I can contribute a similar example, albeit from 2016:
Extension 40 sqm raised ground floor 1m height, also an expensive area, however with a shed roof instead of a flat roof. Costs approx. €3400/sqm (excluding demolition costs).
It would have been cheaper with less glazing (floor-to-ceiling all around 13m) and without an architect (for everything including construction management) and certainly with own labor. I can’t say what the construction cost increases of the last 5 years amount to, but from what one hears and reads, I think it would be considerably more expensive today.
I would also always prefer local craftsmen with a good reputation again, possibly getting a second offer for comparison and also for the interior finishing (in our case the architect planned and tendered locally).
And yes, better to plan more costs in advance and then afterwards spend the remaining money e.g. on the outdoor area (we hadn’t considered that it wouldn’t look as nice outside once the excavator is gone..... luckily our architect planned generously in advance and then tendered well :)
Good luck with the construction & much joy with the extension afterwards!