Hi All!

I am currently under contract on a home and would love to get feedback on the deal and ideas on how to proceed with negotiation. Here are the details of the deal:

The parcel info shows that the lot is zoned for multi-unit but the current use is listed as a single-family home. However, there are two houses on the property. The square footage of the 2nd home on the property appears on the parcel info as an "extra feature" but it does not appear as part of the "heated area." Therefore, I believe the 2nd house on the property is unpermitted. Both houses appear to be in good, safe, livable condition. Considering how competitive the market is at the moment in this area, I made a full price offer with inspection and appraisal contingencies. Considering comps in the area, this property was priced as a 2-unit property and not as a single family home. I suspect the home will appraise for less than what I have offered. 

So my question is, considering the situation with the 2nd house and the possibility that this property will appraise for less than what I have offered, how would you proceed with negotiations on price?

Thanks in advance for your insight!