Zero down a 'misnomer'

Hidden costs of getting into a home with little or no money down include the private mortgage insurance charge that everyone who puts down less than 20 percent must pay.

And in a potential double-whammy, those with lower credit scores will pay more for that insurance, adding to the monthly payment.

Sullivan also noted that even with no down payment, buyers have other things they usually must pay for during the home-buying process. Those include a third-party inspection of the property, closing costs such as bank fees and other charges, and "earnest money" they must provide within days after getting an accepted offer.

"This notion of 'zero down' is a misnomer," Sullivan said. "To get a transaction done, you need to have $2,500 to $3,000 in cash, just to make it happen. So you need to be prepared."

Another concern of putting down little or no down payment is the lack of equity, or ownership stake, it provides in a house.

With no equity, homeowners have no ability to refinance and no built-in fund to borrow against to make improvements to the house. Buyers who don't start with a good-sized down payment also wind up paying more interest over the life of the loan.