The default permissions for /home in ubuntu is drwxr-xr-x or 755. For /home/user it is also drwxr-xr-x or 755. At least it is on my installation.
To change the values you would have to have superuser authority. Open a terminal and do somethings like
sudo chmod 700 /home/user
Remember to change the 700 to the chmod value that you actually want to set. When you run this command it will ask for the administrator password.