Philadelphia - History and Blue Prints of a House

[Alyse Oz]

I looked online for information on a property: https://li.phila.gov and on the atlas system

While I do get a lot of information, I can't see the original blueprint of the home or any other plans.  Do I physically need to go to "L&I Permit Services in the MSB Concourse" to get this information and what do I need in order to get this information?