Duplex Renovation - Seeking advice

[Tom Squire]

Hello BiggerPockets!

I've got a duplex under contract and will be using a streamline FHA 203k loan to bundle a renovation budget of around 29.2k (the limit for Streamline once fees & contingency buffer are included) in with loan. I'll be living in one side and renting out the other. One side is a 2bd/2bath the other is a 2bd 1 bath totaling just shy of 3000 sf.

Kind of a BRRR(without the refinance)/House Hacking combo.

Had the inspection earlier this week and a couple contractors come out for a walkthrough to place a bid.  Its easy to get excited about the counter tops, floors, fixtures, paint, appliances etc. 

One of the things that concerned me on the inspection report is that there is galvanized water pipes and cast iron drain pipes (replaced with PVC once above ground).  I've heard these are costly repairs and are a good thing to do. 

To my knowledge everything works fine, but I'm curious on the importance of replacing these and when it should happen? The house was built in 1959 so it seems like its about to start showing its age.  Luckly the roof was replaced last year (although there are some pretty nasty ice dams from recent storms).

Would love to hear your advice! Happy to share about the 203k process if anyone is interested as well.