New construction cost calculation, suitable for architect?

I was surprised that the division of the trades is calculated on the total sum of €584k (above including buffer earthworks, outdoor facilities & double garage).
These 3 points have nothing to do with the trades of the house.

I can’t make sense of "buffer earthworks" and "earthworks + buffer" totaling around €75k. What are these two different earthworks items supposed to be, and why do the actual earthworks cost nothing here, but their estimated uncertainty almost as much as the approximate budget one should provide for it?
All costs belong in the total calculation because there are no gratis items in construction. Or did you mean that the surroundings should not be included in the basis for calculating the architect’s fee (outdoor facilities planning as a kind of bonus)?

We have not yet created a height & ground survey, so initially the estimate. Masonry concrete 26% of the total amount = €152k. This €152k is completely independent of the earthworks (including buffer), the exterior facilities, and the double garage which comes extra. If the garage is dropped from €54k, according to his calculation the masonry/concrete costs are reduced by 26% of €54k. That makes no sense. The percentages of the trades should be based on the volume, not on extras/exterior facilities. And you think the trades are set too low by a good 20%?

And you think the trades are set too low by a good 20%?

Without knowing the house, the location, the plot, etc.? Yes!!! Custom-built houses with construction companies currently cost +/- €3,000/sqm per sqm of living space plus garage, outdoor facilities, incidental construction costs (so €3,000/sqm for the cost groups 300/400 according to DIN 276). Sophisticated architecture, fittings, etc. can also sometimes go up to €4,500/sqm. Whether it ends up being €2,850 or €3,100, no one knows. But for a good €2,500 the architect must have special reasons – e.g. building in a structurally weak region where craftsmen are currently going bankrupt in droves because there are not enough orders (a somewhat exaggerated example).

The architect really put a lot of effort into that!

Carpenter and roofer will then do the flat roof?

Best regards GD

Whether it ends up being €2,850 or €3,100, no one knows. But for a good €2,500, the architect must have special reasons.

I suspect a classic case of "Gerddieter warns" Architect: university lecturer for ages without construction site experience, construction cost manual from their own study days plus inflation index. Am I wrong: scope of mandate phases 1 to 4?

We received a good recommendation from another builder that the costs that were calculated were adhered to.

Architect is [LPH 1-8].