My lease says that the tenant is responsible for plumbing backups they cause. 

(I think you should) What happens if you miss your closing date or he backs out at the last minute or there is an undisclosed lien or a major mechanically problem with heat, foundation, water heater, electrical, plumbing, etc?

The house still needs to have a second bathroom installed (it has the plumbing) upstairs, and is probably worth $275-$300K as is.

Thought the tenant would have to get a motel, but luckily, was able to keep one bathroom working by installing the new water heater in the hall temporarily.Took about two weeks to replace three joists and rebuild everything, including updating of plumbing and new hot water heater.

I am also assuming that we will need new plumbing.

What you need to focus on is ensuring you are always in compliance with building codes and hiring licensed professionals to do things like electrical, plumbing and HVAC.

I plumbed the gas supply line and the cold water inlet to the gas heater, routed hot water out of the gas heater into the electric heater, then installed the vent through the roof to vent the exhaust. 

For example if everything looks good but the plumbing or electricity haven’t been updated, is that something that’s such a great expense that you’d rather stay away from?

I am also using 5/8 soundbreak xp on my plumbing walls.

✅ Purchase Price of $28K per Door✅ Property Condition Newer Roofs, Well maintained, No Major Foundation or Plumbing Issues✅ Property Characteristics Individual HVAC & Water Heaters, Great Unit Mix, Large Floorplans, Great Amenities Including Pools, Gym, Sauna & Playgrounds ✅ Cash Flowing from day one✅ Conservative Underwriting✅ Cost SegregationHow did you find this deal and how did you negotiate it?