Cost of converting a flat roof to a balcony

The static requirements for a balcony terrace are hefty and mean that you need a different construction. Add a surface covering and a railing, and the price doesn't look so high anymore.

Thank you very much for the answer. Do I understand correctly that the balcony terrace is not on a flat roof at all, but is built entirely as a separate structure? Then the price certainly isn't too wild.
Accordingly, since the flat roof surely already contributed significantly to the price of the house, it should be deducted. Or am I overcomplicating things?

Great house, really well done!

Or am I thinking way too complicated?

The question was not addressed to me, but for us it was like this: Reinforced concrete ceiling for the entire ground floor – included in the price. Flat roof with sloped insulation and appropriate waterproofing – included in the price. Parapet cover made of anodized aluminum – included in the price. So only the extra rows of masonry had to be added to the calculated house price. This was as insignificant for the house price as the plastering of the extra rows of bricks. Additional costs only arose from the protective mat between the waterproofing and the roof terrace and from the actual terrace construction with WPC decking. Best regards Axel

I remembered the information that the load-bearing capacity of a flat roof for the use of people must be designed differently than if the roof is not walkable. This would then result in a different construction if the planned roof did not already meet this requirement.