At the suggestion of an S Scale modeler, we are adding a loading door as an option to the windows on the first floor of the Paterson Silk Mill. For the ultra-creative you could even put the door on an upper level and add a pulley overhead- very common on end elevations of Paterson mills. Your orders may now include the added option of the number of loading doors and windows that you want on the first floor.
If you want to use your Paterson Silk Mill with the warehouse doors at box car loading dock level, you will need to add your own plinth or foundation.
Here's the O Scale version: