If u plan to take the building down as opposed to repurposing it, you may encounter contaminated soil that was previously capped by the slab.the estimate sound low on the low end to me.

My line of questioning here is instead meant to make sure there's no "fear disguised as practicality" underneath the Schooling decision.Assuming the schooling is the right choice for you guys, does it have to be an all or none decision? 

Im sure there is something in the soil.

This 4th property was bought because I just had a baby, we have 3 dogs, and my spouse couldn’t do the commute from vancouver, WA so we bought a house in Beaverton, OR across from work.  9 months living here and it’s way too small and we need a real yard for the dogs- these homes are more like row houses with a small patch of gated soil in the front....We only put 5% down so we will sell at a loss and rentals here are so cheap, if we rent we will take about $400 a month loss....I now stay at home with the baby and manage our properties- I have a real estate broker license so I can claim the loss....Question is- would it be better to leverage the funding and keep this house even with the negative cash flow or just sell it?

We cut into the wall to discover pile wood underneath the airducts collecting water.

Are there a completely different set of rules or regulations once you step outside US soil?

Upon further investigation I found water underneath the tile in the neighboring bedroom.

I've got a rental that has some grade issues on the outside and I am going to add soil to help with drainage away from the house. 

Apparently, the leak washed out the soil under the slab.I chatted with a tenant whose dad is a real estate investor, and he said that's why his dad avoids properties over 25 years old, which ties in with what my plumber advised.

Also, need someone that doesn't mind getting underneath the home to work on plumbing, a/c, leveling, etc.