Bank will only finance with 30% down

[Jhonatan Ramirez]

I'm wanting to use a HELOC to purchase a duplex behind a college. The problem is since it is two single-family homes the same size, this disqualifies it for most loan products. There is a bank that is willing to finance the home with 30% down. I would want to refinance after 2 or 3 years but I'm worrier another issue may come up and I won't be able to pull out my money.

The details: 

Asking Price: $145,000

Brining up to rental standards (repairs): $5,000

1st home 3 bed 1 bath rental: $1,000/ month 

2nd home 2 bed 1 bath rental: $750/ month

Since it's behind a college, there is a possibility to rent one house out on a per room basis for $450/room.

Estimated monthly expenses: $1,350

Estimated monthly Income: $1,750

$100,000 HELOC detail: 3.8% interest for the first year, 6.5% thereafter