Experiences with BG Bau during inspection?

So much for the topic: everything has its reason!
It actually makes 0 sense!

Here, certain factors like vacation, manual skills, speed, etc. are simply left out, which also have an impact on the number of hours. Estimates aside

That is not true. At least the gentleman from BG Bau explained it differently. He told me that when estimating what the builder can accomplish themselves, it is assumed that they work full-time. So they can put in their own work after hours, on weekends, and even during vacation.
And now there are builders who supposedly completed 2000 hours of own work in half a year - at least when you look at the discrepancy between the construction status, work done by companies, and admitted helper hours. This makes BG Bau suspicious. And then the inspection comes.
It happened to me because the office staff didn’t realize that I had bought a partially already built house, where quite a few tasks were already completed.
At what "degree" of discrepancy they take action, I do not know - certainly not if 50 hours appear to be missing.

With us, it was allegedly an error by the internal service. We had built ready for use, so 0 hours of own work.

I at least remember that BG Bau contacted me twice (with a questionnaire), although I had already informed them the first time that I did not intend to do the work myself. So it does not seem to be an isolated case that this is not correctly recorded there at first. Or they want to give the builders the opportunity to possibly correct ambiguous statements afterwards.

And now there are builders who supposedly completed 2000 hours of self-labor in half a year – at least if you consider the discrepancy between construction progress, work carried out by companies, and acknowledged helper hours. This makes the BG Bau suspicious. And then the inspection comes.

I am aware of what you want to express. But if we take your 2000 hours and break them down to a couple, we end up with about 6 hours per day per person. That is very athletic, but not impossible now. When I think about what has been going on at our construction site in the last three months due to the fixed termination of the rental apartment...

Not calculable are vacation, full-time job, commute to work, tiles or laminate, felt plaster or roller plaster, number of coats of paint, etc., and ultimately also the skill of the builders. Can the office clerk not build a wall?

What I want to say is that there are so many individual parameters involved in such calculations and estimates that you simply cannot put them into a "standard program."

I am aware of what you want to express. But if we start from your 2000 hours and break them down to a married couple, we end up with about 6 hours per day per person. That is very ambitious but not impossible. When I think about what has gone on at our construction site in the last three months because of the fixed termination of the rental apartment...

Not calculable are vacation, full-time job, commute to work, tiles or laminate, felt plaster or roller plaster, number of painting coats and ultimately the skill of the builders. Can the office clerk not build a wall?

What I want to say is that in such calculations and estimates there are so many individual parameters involved that you simply cannot put them into a "one-size-fits-all" program.

Exactly that!!!!

I just had the conversation with BG Bau, due to Corona over the phone. Everything very arbitrary and also inconsistent. When the notice is there, I can explain it in more detail, in the end it's nothing more than a horse trade like "You told me X hours, my program says X hours, we agree on the total number of X and that’s that."