@Aaron Mikottis Full interior rehab (electrical, plumbing, kitchen had all new drywall, nee plywood was added on top of old subfloor boards, trims, casing, doors, water heater etc.).

To raise the NOI, you need to increase income and/or decrease expenses.On the expense side, there are some simple methods you can use, such as replacing all of the common area lights with LED's and installing low flow shower heads and plumbing fixtures.  

Any plumbing experts want to take a stab at this issue and see if you can provide a diagnosis?

Another thing to consider is the heating/cooling, plumbing and electrical.  

Also the cost to create a unit would be much higher than I originally thought -- relocating existing plumbing, heating and electrical and adding separate systems is expensive.

I am currently a Plumbing & Heating Project Mangers/Estimator, and withhold a Master Plumbing License in MA/RI.Any help anyone may need please let me know also!

Also, you will never know if there is a problem with the property from the pictures - plumbing leaks, foundation issues, smells from animals or smoking, etc.

Now, if you are doing even a SHRED of electrical or plumbing that requires a licensed contractor, get the permits, get the contractor and obey the law.  

We are 95% finished fully rehabbing (foundation, roof, plumbing, electrical, etc) an investment SFR bought with cash and intend to cash out refinance after the 6 months required (so we don't have to do delayed financing). 

It seems like it is a big space, but I doubt you want to move any plumbing?