House construction: as long as the warranty lasts after house construction

Shortly before the end of the warranty, defects appear in the house construction. Even then, the architect is still in charge. How can claims be secured?

The million-dollar project in Keitum on Sylt had been extensively rebuilt. But the entry into the Reetdach property was long ago. Almost five years had passed, there were dark discolorations in the bathrooms in the first basement in autumn. The owner and builder became restless. The call for the architect was loud.