It should be easier for families to qualify to buy new energy-efficient homes in Maryland, under new guidelines announced this week by the Federal Home Loan Mortgage Corp. (Freddie Mac).

The corporation buys mortgages from primary lenders, increasing the supply of new funds for housing. Lenders are more willing to offer mortgages that they can sell to Freddie Mac or other parts of the secondary mortgage market.

Freddie Mac officials said this week that the corporation would loosen its guidelines on income levels for mortgages on energy-efficient homes. The justification behind the looser regulations is that energy-efficient houses will cost less to maintain so buyers' incomes do not have to be as high.

At a press conference sponsored by the Suburban Maryland Home Builders Association, Freddie Mac spokesmen said that the association's "E-7" energy-efficiency program is consistent with the new energy efficient guide.

This means that buyers of homes receiving the association's E-7 award could qualify will lower incomes.

Charles Hardwick Jr., vice president of Nationwide Lending Group Inc., of Rockville, used as an example a home with an $80,000 mortgage with a builder buy-down of the interest rate to 12 1/2 percent. Under Freddie Mac's regular ratios, to qualify for the monthly mortgage payment of $853.81 a family would have to have a minimum income of $36,600 a year. Under the liberalized rules, the minimum income requirement would drop to $32,000, making it easier for more people to buy homes.