What surprises did you uncover during the rehab, which were not planned for in your budget?  

Yes, theoretically the ADU should increase the value of the home...so long as there is an alternative for parking that's not on the street or uncovered. ...I hope this helps! 

We found a property while driving for dollars and uncovered that this said property was debilitated ,vacant and completely gutted.

You could uncover things about the property during due diligence that would make it a deal you should run away from. 

You really don't know what you are going to uncover on a house like that, right?

I'll update what info that I have found so far and I'm excited to share what I've uncovered so far.

His job is to uncover issues and necessary repairs so that the buyer can make a go / no-go decision on the purchase.The appraisal is done by the lender (paid for by the buyer).  

None of which were uncovered when we did our DD & went to the town BUT he had recently dug through 40 years of archives.

We deduct these from the purchase price but, if we uncover it within the reps and warrants period, the seller is still responsible to pay this.Ultimately, a thorough due diligence process is the best defense against a bad seller.

However, there are owners out there that are willing to be creative if you can uncover their motivation and think of ways to resolve a problem for them.