Service quality of construction companies - Is this still to be expected?

Did I understand correctly: building a house by handshake and without a 5-10% final payment only after defect-free acceptance?

That's how it should be! Negative example with us: After 2 years, doors and windows warped a bit. Called the company, they have only one service team, completely booked, earliest in 8 months. And what if someone breaks in?? Well, hopefully they have good insurance.

I have now ordered one like that, which was also difficult.

Did I understand correctly: house construction by handshake and without a 5-10% final payment only after defect-free acceptance?

Not quite. Defect-free acceptance and final payment were in September 2017.
But VOB stipulates that the retention is held for the duration of the 5-year warranty period. Can be replaced by a bank guarantee. - This regulation significantly increases the cost of building.
Otherwise: handshake agreement is correct.

Trust is your worst enemy in the construction industry. And most defects are still not visible after a year. But good for one's image.

You always have to trust in construction unless you are a professional crawling over the construction site every day: Is the roof frame calculated correctly? Is every tile nailed storm-proof? Is he not mixing the Ytong adhesive too thin? Is the base sealing okay like this? Etc. Some even hire an expert who checks 4-5 times... but when he says everything is fine, the company is off the hook... they have it in writing that everything is fine. Karsten

...and about the value of paper. Hilfehilfe surely has great contracts. It didn’t help at all with the warranty.

...and about the value of paper. Hilfehilfe surely has great contracts. It didn't help at all with the warranty.

right. GU is already busy with his 1058698 new projects and has no interest in us. His craftsmen are working on these new projects. We have paid everything.

So you weigh it up. Get annoyed or simply hire someone yourself