Do you have root access? Most of the time, to edit folders that are not in your home directory, you need to have sudo or root access. If you have root access, you can always make a folder wherever and then change the ownership using
sudo chown *user* /path/to/folder. Then, user will be able to install packages to that folder. If you don't have root or sudo privileges, then you're stuck using your home folder unless you ask the system admin to make a directory elsewhere for you.
I usually put other packages in the /opt folder and none of them are used as root. However, I did install them using sudo, then changed the ownership to the appropriate user after the fact.