Montgomery County Executive Charles W. Gilchrist proposed yesterday that builders provide a warranty that would cover faulty plumbing, roofing and scores of other household problems on new homes.

Under the proposal, which now goes to the County Council, builders would pay a portion of their revenue from the sale of a new home into a county fund, which would be used to pay for warranted home repairs if the builder refuses to do the work. Builders who fail to make the necessary repairs could lose their license to work in the county, under Gilchrist's plan.

"An estimated one out of 10 homes built in the county have problems of some kind," Gilchrist said at a news conference. " . . . This will in effect give homeowners a way to resolve complaints regarding home construction."

The proposal, outlined in a memo to County Council President Michael L. Gudis, provides a "comprehensive builder registration system" and includes a one-year warranty on defects in materials and workmanship and a two-year warranty on plumbing, electrical and heating defects.

Barbara Gregg, county director of consumer affairs, said she received 276 complaints last year from homeowners who were not satisfied with their new homes. Gregg said builders currently pay $15 for a license and are required to carry only one $2,000 bond to cover all new homes.

Some builders already individually offer the new home warranties, and they would be excluded from the county's warranty fund.

Under the proposal, builders would be required to pay 0.3 percent of the selling price of each new home they build to a New Home Warranty Fund. If the home sold for $100,000, the builder would pay $300 to the fund, Gregg said.

If builders go out of business or refuse to make repairs, Gregg said the owners could draw from the fund to pay repair costs.

"We don't expect to be drawing from the fund very often," Gregg said.

"Because if a builder refuses to pay and the repairs are justified, the builder could lose the right to build in this county."