The addition of a construction site set up in the place where the original game had an empty prepared site (via binary IPLs) also adds an entrance and exit to the SFPD interior, based on the Updated Classic updates (38).
Installation:
Unpack the folder in modloader, you may need to remove/extend the limit on the number of IPLs (you can use OpenLimitAdjuster or FastmanLimitAdjuster)
Disclaimer:
This mod is one of a series of fixes included in the Updated Classic Uncover project, whose goal is to refine and improve the approach of Updated Classic builds.
The authorship of the coordinates may belong to someone else.