You can mitigate some of the risk by:Using PEX tubing for the plumbing for anything you replace. 

The vehicle market is moving toward EV so this will save us from a future electrical upgrade.We were converting from knob and tube so the cost of including an EV circuit was insignificant. 

In addition to this site, are the Bigger Pockets you tube channel, Robuilt channel (Rob is also the new co-host of the Bigger Pocket podcast) and of course Avery Carl's book. 

Updates:Audis are not meant to be trucks...my suspension broke...I should probably add that to renovation costs:)Finishing up the floor today, most of the painting is done, new doors and new windows went in, we put together the cabinets and installed them, rewired most of the apartment, eliminated the old "knob and tube" wiring, etc.When they say everything that could go wrong , will go wrong....they are not kidding.

We have some major electrical work to upgrade (old knob and tube, spilt units to their own meter, ect) and would like to add in baseboard heating/ductless ac units.

Oh yeah< and plugged/frozen drain tubes. 

It's probably wise to check the vent and tube at least once per year if not more regularly.

This is about the math, then it is about the math, and after the math makes sense. . . you can then be a big emotional teddybear bout the property.At some price, this becomes a viable and cashcow, moneymaking vehicle.Get a foundation contractor out there and assess the rebuild cost on the property, electrical to look for any Knob and tube wiring, and a plumbing contractor to discover water pressures through the properties.Also, have you thought about Section 8 landlording?

Make sure it doesn't restrict too much.https://www.menards.com/main/plumbing/rough-plumbing/pipe-tubing-hoses-fittings-accessories/fittings/pvc-fittings/genova-3-pvc-floor-strainer-dwv/69230/p-1444431309006-c-8557.htm?

Pistols on hip, Porn DVDs, nude oil paintings, diesel fuel in old beer cans...haha...as long as the strategy is working for him.