There isn't any guarantee that whatever you do will add significant value to the property.

For the vast majority of Conventional, FHA, and VA mortgages you are only guaranteeing the lender that you'll live in the property as your primary residence for a minimum of 12 months.

If one partner unconditionally guarantees the debt, this can sometimes require some side room guarantees to that partner to ensure no one recognizes a capital gain.As a few others have alluded to, there is a secondary problem known as a "debt financed distribution interest expense." 

I guarantee you don't have the right to "sell" that property as you've done because the bank has a lien against that deed which must be paid if/when you sell, and you almost guaranteed to have language that you are supposed to notify the mortgagor if/when you sell the property so that they can exercise their due on sale clause. 

If you do most things right, most issues are mitigated and it's not too bad, but there's no guarantees.

The "Learn more HERE" link takes me back to the Bigger Pockets home page. 

The modeling of this is actually pretty easy (see link: 42-unit proforma sample), but my model treats the pre-refi loan as I/O, but that can be updated based on your deal.

I will check the link you put above.

The mold remediation companies should have the skills to identify the source, suggest a solution, and give you a bid with a guarantee of their work.

So, Benjamin, if you're American I would give that some thought.Below is a link to a forum thread in which I outlined why, you can read if it'd be helpful.