Buying neighbors house.

[James Dresdin]

Good Evening, I have a what seems like easy question but the more I dig it is very complicated. Here we go.   

I have lived in my house for a few year and currently have it mortgaged. My neighbor recently put his house up for sale. I made an offer and he accepted. The house is under priced and I feel with 10-15k I can gain 60-70k in equity in a few months of work.  The current owner still has a small mortgage on the property. 

Here is what I want to do and I'm trying to figure out the best way. We both have square 1/2 acre lots. No HOA only county zoning. Lots in the area differ and nothing is standard. I want to extend my property line over 15ft. This would leave the new property with 15ft from house to property line vice 30ft. The county only requires 7ft between structure and property line. The other side still has 40ft to the property line.

This gives me more room to build my “garage mahal”.   

I’m only a few days into the purchase process but I’m wondering if this should be adressed now or after the sale.   Thanks in advance.