Philadelphia: what's the rule regarding insulation?

[Russell Volk]

Hello everyone,

I wasn't sure where to post this, but here's my situation.  I'm currently in the process of rehabbing a house in Philly.  It's an interior unit row home with basement, 1st floor and 2nd floor.  Got all my permits.  Inspector from L&I came out and said that the front and back walls need to be insulated.  So I noted that and after he left, I realized that in the basement, I will be taking down the interior drywall, but one the 1st and 2nd floors, drywall will be placed on top of the existing drywall.

After the inspector left, I tried calling him, but I can't get in touch with him, so I thought I would ask someone here.  I have 2 questions:

1. Since I will be removing existing drywall in the basement, I'm sure I have to insulate the walls before I put new drywall down.  But what about 1st and 2nd floors?  I'm not removing the existing drywall.   Should I still insulate them?

2. Inspector told me that whomever does the insulation, they need to provide a certificate that it was properly done.  I know I can rent a machine that blows insulation from Home Depot.  Obviously, there will be no certificate if I do it myself.  Do I have to hire a company to insulate the walls?  Can I do it myself?

Those of you with experience, please point me in the right direction.  Dealing with L&I in Philly is an absolute nightmare.

Thanks in advance.