He currently has about $10,000 cash and about $20,000 in credit "Home Depot line of credit for materials."

The catch: my partner just sabotaged his credit and is self employed.

I get these lines of credit/ mortgages off my investment properties that are rented.

I was planning on purchasing a 400k MF with cash but was planning on getting a line of credit on the piece in order to handle any "expected" surprises. 

Since I found the BP website about 4 years ago I have dedicated myself and I have all the time I need and spend all I can on the internet and I read a book about every two or three weeks. 

Also, it would be wise to get some credit lines just to have in case as well. 

I have little income with good credit.

@David MoreheadBooks: Due Diligence Handbook (super important and often missed element of the underwriting process)The Real Estate Game: The Intelligent Guide To Decisionmaking And Investment (solid overview by an experienced operator)How to Create Lifetime Cash Flow Through Multifamily Properties (free, solid book)Articles:How to Avoid the Most Common Commercial Due Diligence MistakesDeal Screening Checklist for Passive Multifamily InvestorSpend time poking around the Internet + networking with local multifamily investors to understand how to underwrite and what assumptions to use. 

It will most likely be a line of credit with a second lien deed of trust (2nd mortgage).

As long as your partner has good enough credit and documentable income, and assuming that together, you both can qualify for the loan, then it is possible to purchase the house this way and basically house hack.