Charles County commissioners proposed banning construction of single-family houses smaller than 2,000 square feet yesterday, saying they want to prevent a surge of cheap homes from builders thwarted by restrictions recently enacted on town houses.

The proposal, aimed partly at bolstering sagging housing values, would eliminate the bottom third of the market for new detached homes in the Southern Maryland county. Critics said it would crimp housing options for working-class families.

The move, which faces public hearings, is the latest in a series of responses by outlying suburban governments to curtail rapid, budget-busting residential growth.

It may also be the most unusual. Building industry representatives in Maryland and Northern Virginia said yesterday they knew of no other jurisdictions moving to regulate the size of new single-family homes.

The typical 2,000-square-foot home has two levels and includes three or four bedrooms, 2 1/2 bathrooms, a living room, a family room and a kitchen, said Gopal Ahluwalia, research director for the National Association of Home Builders. It's a space slightly smaller than a singles tennis court (2,106 square feet), or about the same floor space as that contained in three Metro rail cars.

Ahluwalia said 49 percent of homes built in the United States in 1998 were 2,000 square feet or less. "It's an average-looking house," he said. "It's not small."

Charles County officials have been struggling to cope with demands for roads, schools, policing and other services for a population that has jumped by one-fifth this decade, to roughly 123,000 people. Commissioners this year reluctantly raised property taxes for the first time in eight years.

Yesterday, the five commissioners voted unanimously to send the proposed ban on smaller houses to the Planning Commission, whose members they appoint. After planners issue a recommendation, the proposal comes back to the elected commissioners for a final decision.

"The base concern we have is the amount of development . . . and the quality of the development and the health of our neighborhoods," said Board of Commissioners President Murray D. Levy (D-At Large).

Levy referred to drops in housing values in the rapidly growing Waldorf area in northern Charles County. "We're trying to raise the bar without excluding people," he said.

In the last year, jurisdictions including neighboring Prince George's County and Virginia's Prince William County have moved to reduce the number of town houses being built, usually through increases in fees charged developers, as in Prince George's, or a revision of zoning codes to limit the number of buildable units, as in Prince William--or some combination of both. Planners in Loudoun County have stricken some 70,000 prospective homes from their maps.

The proposed Charles County restrictions open a new phase in a debate joined in earnest last year when commissioners imposed a moratorium on town house construction. They cited concern over dropping property values, rising rates of absentee ownership, crowded schools and increased crime.

Critics said housing stock had little to do with such trends. They cited independent studies--one by economists hired by the commissioners--tying troubled property values to a lack of good jobs in Charles County, where most job growth has been in the lower-paying retail trade.

The moratorium ended early this year as commissioners imposed elaborate restrictions on town house builders. The effect has been dramatic: Charles County builders have applied to build 12 town house units so far this year, compared with 233 at this point last year.

Builders' representatives were quick to point out that there has been no recent trend toward small houses that might be considered a substitute for town homes.

"I don't think there's that big a problem," said F. Hamer Campbell, director of government relations for the Maryland-National Capital Building Industry Association, a trade group. "This is government attempting to control the market."

Several advocates for moderate housing spoke before the commissioners.

"I don't like it at all," said Jazsma Speece, 47, who lives in Brawners Estate, a community in western Charles County built with help from a nonprofit organization.

"I think it would be a sad thing if you say to anybody, 'If you don't make enough money or your money isn't big enough, that you can't live in the county,' " Speece said.

The average detached home built in Charles County in the last two years has a living area of 2,270 square feet, said assessments supervisor Robert C. Farr. Farr said such homes sold for an average price of $198,683.