You can live in one unit and rent out the other for little to no down payment.

True re the prior poster, re this helping the seller save their credit, if you buy sub-to you will dramatically raise their FICO since the mortgage will show on-time payments.  

I was thinking he supplies the down payment and acts as a silent partner.

Appreciation of an asset with low down payment, tenants paying principle down, tax advantages, all reasons why real estate is an investment of DOING.   

@Jaycee Greene I wouldn't have the funds for the down payment. 

You can even plan vacations that are written off if using the sandwich method by doing work on Friday and Monday for real estate and the weekend is there so you do vacation stuff so all lodging and travel can be written off. 

. - Fortunately, our transparent systems allowed the owner to catch it:)- Full transparency - we would have never caught this honest mistake:(An owner also needs to be involved to approve & fund large expenses: maintenance, property tax & insurance payments (if they want to be more hands off), evictions, etc.A great PMC should also have a chat with you annually about your future plans for a property and your portfolio. 

In theory, since we don't have a prepayment penalty, you could borrow the money, complete the rehab and pay off your loan before your first payment was due.

The other method is to use a “safe harbor”, i.e., the specific procedures laid out by the SEC in Regulation D.  

Wealth-drivers are appreciation, debt pay-down (ie. principal payments) and tax shielding.