The NAHB's top executive blasted mortgage lender Fannie Mae for the government-sponsored group's plan to impose a 25-basis-point surcharge on all new mortgages that it backs or purchases after March 1, 2008.

Jerry Howard, the NAHB's president and CEO, called the new surcharge a "broad tax on homeownership" that will ultimately be passed on to new home buyers. The surcharge, called an Adverse Market Delivery Charge, amounts to roughly an extra $1,000 in fees on a $400,000 mortgage.

Fannie Mae's new surcharge comes on the heels of two other moves by the lender that affect the cost of credit for new home buyers.

According to the Wall Street Journal, Fannie Mae has begun imposing surcharges on borrowers who have credit scores below 680 and are borrowing more than 70 percent of a home's value. The fees range from a high of 2 percent to a low of .75 percent for scores of 620 to 680.

In addition, Fannie Mae has started raising down-payment requirements for the loans it buys or guarantees in markets where housing prices are in decline. In such regions, which would include troubled markets such as Arizona, California, Florida, and Nevada, lenders must cut by 5 percent the maximum percentage of the home's estimated value that can be financed.

"While we understand that over the last few months Fannie is looking at the risk of loans and pricing accordingly, we also think Fannie has a mission to help out the housing industry," Howard said.

"At best, the latest surcharge is bad judgment, at worst it is piling it on," he said. "It's certain to be more difficult for the housing market to regain its footing when steps are being taken to drive up mortgage costs."

When asked to comment on the latest surcharge, Brian Faith, Fannie Mae's managing director for communications on new pricing and charges, would only point to a brief statement the lender released Dec. 7.

"Fannie Mae has undertaken a series of steps to establish new pricing and charges for our business to ensure that what we charge aligns with the risk we bear," Faith said in the statement. "These changes reflect the ongoing turmoil in the mortgage finance markets."