Borrowing someone else's credit (tell me what I need to know!)

[Dan Cumberland]

Hey everyone!

My wife and I want to get into a place that we can house hack a bit on the north side of Seattle.  The challenge is that the market is hot, our income isn't huge, and duplexes are pricey.

We have a few friends with great credit and income owe us some favors.

It seems like if we can have someone cosign to borrow against their credit, we could get into a duplex where 2/3 of the mortgage would be covered by the other unit.

What do I need to know about cosigning or borrowing someone's credit?

Thanks for the help!

-Dan