BUILT 1964 during a drought so city put a limit on plumbing.

In the engineering department, I probably want to have experts in electric traits, plumbing, heating and air conditioning, flooring, etc.

I completely rehabbed the systems of this property with new electrical and plumbing systems.

You may want to check with your bldg inspector as some will allow the owner to do a lot of the rehab as long as you get the required permits.As mentioned above the HVAC, gas lines (& bonding if CSST is used), plumbing, electrical service panel &/or sub-panel wiring needs to be inspected as well as the required GFI's etc.

(electrical, plumbing, painting, adding two bedrooms, etc) Also added a privacy fence and a deck.

All new HVAC, insulation, electrical and plumbing including gas and sewer.

LED lighting, new electrical panel, new plumbing, new central heating and A/C for maximum safety, comfort, and efficiency.

And like most other problems (i.e. electrical, plumbing, foundation, etc), they can generally be fixed. 

One of the tenants (and only one) is complaining that he can hear 'snapping' coming from the pipes at all hours of the day (so he says)- which is likely from the plumbing expanding and contracting.

All houses have brand new hvac, new water lines to the street, new plumbing to the street, new flooring, new kitchens, interior/exterior paint, new bathrooms, 1 has new roof etc ect etc.