lumqal
The Buildings 'staircase 18' to staircase '27' are incorrectly modelled. They are all 3 story buildings which share a common basement. This common basement goes all the way from the William Doo Building to staircase 27. The photo was made from the point of the note looking towards staircase 21.

via StreetComplete 39.1

Attached photo(s):
https://westnordost.de/p/78399.jpg
https://westnordost.de/p/78400.jpg