Creating a directory in /home on MacOS Sierra
IIRC /home and /net can be used by directory services like AD or OD. They are mount points created by the auto_master file. Usually they are not used for anything - especially on non-corporate Macs.



Comment out the line /home         auto_home   -nobrowse,hidefromfinder in the file /etc/auto_master and enter sudo automount -vc or reboot. 

Then you should be able to create /home and any further subdir with sudo mkdir -p /home/subdir.

If you are done with your PHP legacy code remove the folder /home and its content and restore the old auto_master file by uncommenting the /home line.