For many New Yorkers, home ownership -- whether co-op, condo or house -- is the first step toward building wealth. And making that first home easier to finance can give families an important toehold in the middle class.

That's the great thing about Fannie Mae and Freddie Mac's recent decision to underwrite mortgages with down payments of 3% for first-time home buyers.

Previously these two guarantors of most of the nation's mortgage debt bought only loans with at least 5% down. Now more hardworking families will get a shot at upward mobility.

And expanding access to mortgages for people who can afford the monthly costs of ownership but don't have a big pile of cash to put down -- such as families burdened with college debt -- should provide a small but timely boost for the sluggish housing market.

Nobody wants to return to the days of dicey mortgages that borrowers can't afford -- like the ones that inflated the housing bubble nationwide and led to widespread bank collapses starting in 2008.

But safeguards with the 3% loans will limit risk:

Existing credit requirements will not be relaxed.

Income will have to be documented.

Only vanilla fixed-rate mortgages will come with the 3% down payment, not those with low teaser rates and balloon payments that got many borrowers in trouble. The loans will be available only for primary residences. Borrowers must have private mortgage insurance.

History also offers an encouraging precedent.

When 3% loans were available in the past, says Fannie Mae, the default rate was essentially the same as for those with 5% down.

Still, borrowers at 3% will be required to complete a buyer-counseling program.

Expanding the chance to own a piece of the American dream isn't completely risk-free. But what is? This risk is worth the gamble. Fannie Mae and Freddie are betting on a stronger middle class. That means a stronger New York.