The latest round in the long-running struggle over the future of rural Loudoun County is set to continue at least through the end of the year, county officials said.

The next step will be two public comment sessions next month on competing rural zoning plans. The evening gatherings July 6 at Loudoun Valley High School in Purcellville and July 11 at Stone Bridge High School in Ashburn recall similar sessions held during the three years it took a previous board to hash out plans for the western two-thirds of the county. Strict building limits were passed in 2003 after hundreds of hours of public meetings.

But the political make-up of the board has changed since the last attempt to curb home building in western Loudoun, a 300-square-mile area that has stunning vistas, historic communities and a mix of established homes and new, mostly upscale suburban developments housing some of the Washington region's newest migrants.

The board elected in 1999 included eight members who promised to curb breakneck home construction in Loudoun. The Republican majority on the current board was elected in November 2003 after many GOP candidates sharply criticized the growth-control measures imposed by their predecessors earlier that year. The race was shaped in part by an unprecedented influx of campaign contributions from representatives of the development industry.

Over the coming months, county officials will make choices that could affect the county's development for decades. In addition to the debate over rural Loudoun, landowners and developers are seeking permission for tens of thousands of additional homes in more suburban parts of the county, including near Dulles International Airport.

On Tuesday, the Board of Supervisors decided to move ahead with two rural zoning proposals. Among the questions facing officials and residents as they and others debate the plans are how the proposals would affect property values, rural businesses, home prices, local taxes and the environment.

The proposals being considered allow more development than the 2003 rules but less than under the current three-acre zoning. Both have backers and detractors on the board and among landowners and activists.

After Virginia's Supreme Court threw out strict zoning rules from 2003 on a technicality, a local judge restored decades-old zoning requiring three acres per home.

A proposal by Supervisors D.M. "Mick" Staton Jr. (R-Sugarland Run) and Bruce E. Tulloch (R-Potomac) would require 10 acres per home in northwestern Loudoun and 20 acres per home in southwest Loudoun. Landowners could build twice as many homes if they are clustered to preserve open space.

A plan originally put forward by Supervisors Jim G. Burton (I-Blue Ridge) and James E. Clem (R-Leesburg) allows property owners with 20 or more acres to subdivide and build a home on every 10 acres in northwestern Loudoun. In the southwest, owners with 40 or more acres could build a home every 20 acres.

That plan includes a proposal by Supervisor Lori L. Waters (R-Broad Run) that would allow landowners to build more homes if they sought board permission and agreed to provide funds for roads and other public projects. They would be allowed to build an average of one home per 71/2 acres in the northwest and one home per 15 acres in the southwest.

The 2003 rules invalidated by the Virginia Supreme Court would have restricted home building in western Loudoun to 10,000 more homes. Three-acre zoning would allow 46,000 more homes. Staton and Tulloch's plan would allow 20,000 new homes. The Clem-Burton plan would allow 14,000 new homes.

The board has asked two advisory bodies, the Zoning Ordinance Review Committee and the Rural Economic Development Council, to comment on the plans.

After the public input sessions, the board will meet July 13 to discuss policy questions. The county Planning Commission is also expected to weigh in. Letters will be sent to property owners outlining the changes, and one or more public hearings will be held.

County officials said they expect to have the new rules in place by the end of the year or early next year. Opponents of any changes said they are likely to challenge the new rules in court.