Plot in flood protection area - Not recommended?

Many BUs basically build a white tank

I don't believe that, because "expensive" and possibly not justifiable to the customer.

What I do agree with: many build a basement from the outset always properly sealed. Because strictly speaking, there are only sealed or unsealed basements, and if professionals are at work, even simple foil can make a basement completely watertight if applied in multiple layers and glued or welded at pipe penetrations and joints.

For the house planned here, however, every construction company will do everything from the outset to make the basement watertight and will charge accordingly. No one takes the risk of saving at the wrong end here. The determined groundwater depth does not say much, as it is probably dependent on the water level. During snowmelt, the groundwater level may be higher, in late summer lower.

Thank you for the assessment. Yes, presumably construction companies can afford that. However, if it is "only" about making the basement watertight, that is still somewhat foreseeable if you calculate generously. Do I need to consider anything else that might possibly be necessary in this situation? What about protection against uplift now? Might something else be needed here? Or does that rather apply during the construction phase when the base slab needs to be secured or groundwater held back?

According to the buyer information from the engineering office that prepared the soil reports, they wrote the following regarding the building foundations:

"Given the prevailing soil conditions, buildings can generally be founded on shallow foundations (strip, individual footings, elastically supported slab)."

Does this mean that as A RULE it can also be assumed that elaborate foundations, for example with piles, are not needed?

So does that generally mean that complex foundations, e.g. pile foundations, are not needed?

I don’t see a carte blanche or a negative certificate in my crystal ball. But you yourself could see something: the expert report should also have a "visual section," i.e., a map showing the locations of the boreholes. There you should basically be able to recognize the (non-)homogeneity of the building area. The more dissimilar the borehole locations are to each other and the farther they are from your property, the more likely it is that a specific investigation of your property could yield something completely different.

In any case, have a soil survey done on the specific property before construction starts.. do not rely on the few boreholes that have already been made.

Otherwise, I don’t see it as that critical, I would definitely build without a basement, quite simply.

And yes, the insurance can exclude you, so simply do not insure flood damage at your place.

There are also thousands of buildings here at the Paar where it is just like that ....