It really stinks when you buy a property at market value, thinking it'll cash flow only to find out that the plumbing isn't up to par, that the water heater is going out, and that the oven is a relic from the late 70's. 

For my area you really start to get more issues in the 1940s where you have things like knob and tube wiring or non-copper plumbing that needs to be replaced. 

How didn’t the inspector look under the sink to check the plumbing or notice the cuts in the floor for the french drain stop and then pick up on the other side of the the basement?  

Plumber said there might be a grading issue so I need to have the plumbing camera'ed.

Kitchen Double Sink PlumbingI just had my kitchen double sink plumbing redone.

Then the hardest part came; I had to cut a hole though the 4" Concrete foundation slab to access the plumbing underneath.

Major items in the renovation include:Level floors, Lay new peel and stick vinyl throughoutRemove wall heater from bedroomRe-sheetrock in living room to smooth out wall (tie control thermostat wires in wall to provide power on roof)Install new plumbing runs throughoutInstall new drain lines where applicableInstall water line and in-wall box for refrigerator ice makerInstall new tubInstall new tile shower surroundMove over all light switches away from door trimRun wire to two new living room lights, install three way switch outside of bedroom and exterior patio doorInstall new light and wall switch in bedroom closetMove bedroom door 6-7 inches to the south to allow construction of half wallDemo existing living room closet and construct half wall (replumb gas and electrical as required)Demo kitchen cabinets, pantry and counterInstall sheet-rock over water damaged hardboard in bathroom and bedroomsInterior Paint throughoutInstall new bathroom vanityInstall new bathroom lightInstall new kitchen lightInstall new cabinetsInstall new granite counter topsInstall new AC registers (bedroom and bathroom)Install new toiletInstall three (3) new six-panel doors (bedroom, closet, bathroom)Install new outlets and coversInstall new switches and coversAgain, my four estimates for this work range from $14,000 to 25,000 and would complete in 2-3 weeks.

Scale of work is ongoing but includes significant foundation repairs, new siding, new landscaping, as well as minor electrical and plumbing.

I am guessing it would be that it is a very profitable asset type with low maintenance, no plumbing, HVAC and minimal electric.

I paid $200 for a plumbing call out that I could have handled myself with a $5 part.