A stone building (with an entrance through Fidelgasse )was built in the immediate vicinity of the Danube site in the 12th century. This stone building is now the vaulted cellar (partly used as a storage room for the apartments). The walls of the vaulted cellar still show the stone block structure of that time and the windows and staircases into the rear side stone house. This house structure has been preserved from the 12th century until today.

A presumably larger wooden post construction is placed on the preserved foundation walls. This Gothic structure has been preserved undamaged to this day.
The building continued to be used for storage and trading purposes The building along Fidelgasse housed the residents of the house. The rear tower was used as a warehouse.

The steadily increasing prosperity of the city of Regensburg due to its commercial importance was also evident in Fidelgasse 8. In the place of today's communal kitchen, a smoke kitchen was built and the previously used outdoor kitchen was abandoned.

The establishment of the permanent Reichstag also brought prosperity to the bourgeois residents of Fidelgasse 8. The rooms along Fidelgasse were converted into splendid rooms with stucco ceilings, box ceilings, stone walls and paintings. The archway framed by sandstones was created as a visible sign of prosperity during this time.

As a further formative construction phase of the house, existing storage rooms were converted into living rooms around 1836 and 1870 and floors were added above the archway.