One house and a vacant on one contract?

[Eric Greenberg]

This is my first post and first investment property!  I am finalizing up a deal for a house with a vacant property adjacent to it.  Both properties are with the same owner but with separate tax IDs/deeds in Philadelphia.  My mortgage lender did not realize that the properties have different deeds until right now.  My goal is to eventually sell the lot and rent the house. My lender's first thought was that I could not lump both properties together on one contract but wasn't 100% sure.  Is that a true statement?  Do other banks have blanket mortgages for multiple properties owned by the same owner?  

If I need to split the properties into two contracts, I will not be able to get a mortgage for the lot.  I could purchase the lot for $1 and the house would be the only thing on the mortgage.  The issue then becomes the house most likely will not appraise for the total selling price and I will have to come up with the price delta.  Is there any option out there I am missing?  

Thanks in advance!