Partnership with land owner and builder to parcel off land with a mortgage

[Laura Casner]

I've been trying to work out a deal with a land owner who would like to sell off a parcel of land in order to reduce is debt. However, He still has a loan on the property. If I buy the parcel from him, how does that effect his loan? Won't that make his payment actually go up by reducing the value of the home which is now on 1/2 the land it used to be? So if he refinanced then he'd actually have a higher payment after paying in what he was paid for the land?  Can someone help me wrap my head around this with real numbers?  Lets say current appraised value is 170k.  He parcels of .5 of his 1 acre and sells it to me for 40,000.  Thanks!