Single-family house assessment 170m² - construction cost overview underestimated?

Well purchased, I would call it yes, including base cabinets

With a basement or without?

The house is located on a slope.

We built 200 m2 plus a double garage, the construction costs were around 1,600 per m2 with high-end fittings and many extras.

We have just finished the planning and calculation of a 175sqm townhouse villa. Planning with the architect resulted in:

€315,000 house construction
€31,000 architect fees
€20,000 painter/flooring
€20,000 outdoor facilities

Plot and other ancillary costs are also more regionally dependent and would not be further compared, all in all I also believe it is too cheap.
In the end, with the plot (€100,000) and the missing ancillary building costs, we come to €535,000.
About €1800/sqm of living space is certainly not wrong considering the region. With that, we hope to reach our goal.

Best regards