It's no secret that it's much more difficult to qualify for a home loan today than it was in the past. That's unlikely to change any time soon, Fratantoni suggests.

The tight lending guidelines are the result of lenders' new conservative attitude toward the risk of bad loans and the real possibility that Fannie Mae or Freddie Mac will force them to repurchase sold-off loans, sometimes due to technicalities. When lenders are forced to buy back loans, they lose money.

Lenders are being "extremely cautious" and asking for "voluminous documentation," Fratantoni says.

For borrowers, that can mean multiple credit checks, income verifications and appraisals.

Borrowers seeking a low down payment loan insured by the Federal Housing Administration, or FHA, also will be subjected to higher standards in 2011, due in part to lenders' added-on requirements, known as "overlays."