Can I add the other half of my duplex to my current mortgage?

[Laura Cardenas]

Hi BP world!

If you've read my bio or other forum posts then you know that I own half of a duplex.. Well, the owner of the other side has approached me several times over the last year asking if i want to buy his half. Today I ran into him outside and he asked me again, this  was the first time I really dug a little further with questions. I said what are you looking to sell it for, he said I'd like to get at least 70.. I said if I don't buy it are you going to put it on the market? He said no I plan to call one of the home buying companies, because it's going to need quite a bit of work. I said let me talk to my SO and i'll get back to you. 

So here's my question, is there a way to purchase his half of the duplex and merge it into one mortgage loan since it's under the same roof?

Also, any tips for when I do go back to him with a proposal? I was thinking I might say something like "Give one of the home buying companies a call, find out what they'd pay and I'll likely be able to do better"... how do you feel about this?

Thanks in advance!

Laura