A group of U.S. home builders is asking Congress to pass housing finance reforms to ensure that mortgages remain affordable and the market stable.

The National Association of Home Builders proposes changing government-backed Fannie Mae and Freddie Mae to a system over time where conventional mortgages are backed by private money and a privately funded federal mortgage-backed securities fund.

"Multiple stakeholders have now weighed in with their proposed approaches to this important task,” said NAHB Chairman Rick Judson. “While the details of those approaches may differ, one thing they all have in common is the need to maintain some form of federal support to the conventional mortgage market. That's the point from which we believe Congress should start as it charts a path for the eventual wind-down of Fannie Mae and Freddie Mac."