For reference (for those who know the area) its about 2 blocks off Mt Tabor in SE Portland with a part view of Mt Hood.What to do? 

At the end of 2020 I purchased a restoration franchise called AdvantaClean that services from Chapel Hill to Fayetteville, Sanford to Dunn which amongst other things specializes in Mold, Water Damage, and Duct Cleaning.   

Spending hundreds of thousands of dollars because you have already spent a few hundred is not sound business thinking.Your damages won't be worth legal action, but citing their missteps for why you should walk with your earnest money seems sound.

Question for new builders- if a lot is In a flood zone would it be required to have flood insurance if the foundation is built up, on cement blocks?

Also mentioned I could take off the security deposit depending on damages if he moves out, and can give him an 18 month extension to pay rent free.

I had two reasons, one, if the person left early I could put it in the market quickly and two, I did not want any issues or damage to the property.

I recently bought a house with fire damage and need plans for new trusses.

We always ask guests what improvements they would recommend, and then we block off a few days to make those improvements.

It's a solid block structure with 2 units on top and 2 on the bottom.

If you are looking at Student Housing, check out posts from @Will Gaston, he's been around the Student Housing block and then some.