Older (1950's and older) San Diego multi-family

[Mike Hsiao]

I've been looking around San Diego for small multi-family properties.  I've come across a few interesting ones, but they are built in the 1950's, 40's and 30's.

I know some of the things that I need to consider in these older properties when deciding what price to offer is potentially upgrading the plumbing, electrical, insulation, etc.

So I wanted to get some feedback on how to get a sense on how to estimate the costs to repair plumbing and electrical?

I was thinking during the inspection phase, I would hire a professional plumbing and electrical inspector, in addition to the normal home inspection.  Can they get a pretty good feel of what needs to be repaired/upgraded just by looking at exterior features?  I know it's impossible to truly know what's going on without opening up all the floors and walls, but just curious how others here go about this with older properties?

And what other things I should consider if I move forward with an older property?