The Howard County Council has tentatively approved a developer's plan to turn a 36-hole golf course into a "planned golf course community" of up to 4,000 residents, despite the misgivings of nearby property owners who fear an invasion of low-cost homes.

The development is slated for construction on 500 acres of land surrounding the exclusive Turf Valley Country Club. The land is bounded by I-70, Route 40 and Marriottsville Road north of Columbia.

Developer Nicholas B. Mangione convinced the council two years ago to place the club in a special zoning category to allow development on the property without sacrificing the two championship 18-hole golf courses.

The country club was designated as a "planned golf course community" in the county's master plan, and two weeks ago the council took the first steps toward rezoning the land to permit construction of clustered housing, offices, commercial buildings and a hotel.

"The idea is to preserve the golf courses and develop a mixed-use community around it with as much green space as possible," said Louis Mangione, an executive with Nick Mangione Family Enterprises, the developer.

"That's the only way we can keep the golf courses, because the land is too valuable and the maintenance is too expensive otherwise," said Councilman Lloyd Knowles, who is chairman of the county zoning board.

Although plans call for construction of up to 1,000 apartments, town houses and detached homes, county planners said overall development will not exceed two dwelling units per acre, the limit set by current zoning.

Area residents, however, have raised concerns about building town houses and apartments in a rural area of the county that now contains only single-family homes.

"We have no serious objection to the hotel or commercial zoning, we just don't want low-cost homes right in our back yards," said Robert W. McKee, one of 22 homeowners who live near the club.

The town houses are expected to sell for about $80,000, compared with sales prices of $150,000 and up for existing single-family homes, according to residents.

The council will hold a public hearing on the rezoning next week. Its tentative plan calls for low-density development near existing single-family homes. Apartments and town houses would be built along Marriottsville Road, while commercial and office construction would be centered at the club house.

Once the rezoning is approved, the company plans to start construction by mid-summer on a five-story hotel with 140 rooms and a conference center. Over the next 10 years, the company also plans to build a 12-story office building and an eight-story apartment complex at the club, Mangione said.

Although the area is largely undeveloped, Mangione said the club has good access to I-70 and Route 40, two of the county's major east-west thoroughfares.

County planners, meanwhile, said other developers can take advantage of the new zoning category if they meet the zone's minimum requirements of 500 acres of land and a 36-hole golf course.

"It's a unique zoning category. There's nothing like it in the Baltimore-Washington area," said Mangione.