Architect's house in Pforzheim - Offer too expensive?

Hello,

we are currently planning our single-family house in Pforzheim with an architect. The budget was actually 400k. Yesterday I visited a local general contractor who looked at the plans and said he wouldn’t even calculate under 500k. However, it must be said that this is completely move-in ready including incidental building costs (How they can calculate that I find a bit strange anyway, as you can't say exactly beforehand).

I had previously received an offer from Haus der Handwerker of just under 410k without incidental building costs. Also completely move-in ready with solar system and central ventilation (not KfW 55). Heating is district heating.

I’m a bit shocked now because the gentlemen at the GC are calculating a flat rate of 2500€/sqm just for the first estimate. According to his cost breakdown, our architect comes to 460k including outdoor facilities and garage. How would you evaluate the offers? I’m attaching the floor plan and elevations, maybe then it can be better assessed.

Regards Steffen

And what exactly does the architect's cost breakdown say?

With ~185m² plus almost 80m² of basement, I would also be surprised to stay so clearly under 500k.

House 397k
Detached garage 17500
Incidental building costs 37k
Outdoor facilities 12k

where the outdoor facilities are significantly underestimated.
But that has nothing to do with the house.

I additionally obtained a calculation from Spektral for a single-family house with 3 full floors without basement, painter, floor coverings and incidental building costs for 340k with approx. 240 sqm living space!
Now I have 200 sqm plus basement and they want 430k, equipment similar to the first offer???

Would it be advisable to get an offer from an architect?
And are there any experiences with [Haus der Handwerker]?
I mean in principle it’s a great thing if it works.

The general contractor's estimate is not that bad; we are currently at €2400/sqm in the ongoing construction project

Simply assume additional costs at 30% of the turnkey fixed price, then you are on the safe side, i.e. with a bit over 500k

The general contractor is basically saying, I have so many orders, I actually don't want to do the calculations. Why shouldn't Haus der Handwerker work? I would take a closer look at them. Karsten