You need to spend $10s of thousands if not $100s on drawings elevations civil engineers planners before you pay the plan submission fees to get in the door and they can say no or you need to make amendments that cost more $$$

Now that I've graduated, I want to really dig into real estate investing with hopes of eventually replacing/exceeding my full-time income. 

I know the roof was replaced 3 years ago as well as 3 water heaters.

We do not currently have the funds to absorb a failure of the heating system, but there's enough income to budget 10k annually for capex and still hit a 10% cap rate, so it's something we could remedy within the first year or two.I reached out to a business contact and asked if he would secure contingency funds in exchange for a percent of AFFO (basically, we'd pay him a portion of the income in exchange for the right to use him as a private lender in the event that one of the systems failed before we replaced it).

That's where you really scratch your head.This is rather generic, but I don't know why so many tenants refuse to replace light bulbs. 

I'm Kathy -- I work in tech in SF as a software engineer making mobile apps.

This past May, the HOA replaced the roof and is currently also replacing the siding to the outside.Both four plex's are identical so for this breakdown, lets focus on the first four plex. 

I hate carpet and have gotten tired of replacing it after 35 years of investing.

The free forums are great for idea gathering (and yes, this website is supposed to be solely for real estate), but the forum is no replacement for a good professional who knows the full scope of your situation.

Personally I haven't considered my primary residence an investment, probably because when I retire I will probably want a different type of home, but unless I move away I will likely spend as much on a replacement or more.