Fairfax County officials are considering changes to the process used to approve residential construction, a move intended to reduce the conflict that often erupts when new homes are proposed near existing neighborhoods.

During the next 18 months, county officials will meet with residents and builders to discuss possible changes to the way the county handles residential "in-fill development." Several supervisors said yesterday that new regulations are overdue.

"In-fill is the most controversial thing we do," said Supervisor Gerald E. Connolly (D-Providence). "Put in six new homes in an existing, stable neighborhood, and it is a matter of acute concern to the existing neighbors."

When Fairfax County subdivisions were first being constructed, developments were usually built on open land far from existing homes. Now, of course, that's all changed.

Most of the development proposals in Fairfax, even in the western part of the county, affect established areas, and neighbors often complain.

Over the next 18 months, officials will look at how to minimized the impact.

"What we are focused on is how the development fits into the established community," said Supervisor T. Dana Kauffman (D-Lee).

Some steps under consideration include requiring developers to leave mature trees at the boundary lines between old and new development.

A recent example of the kind of development controversy that can erupt in supervisors' faces was the proposal to develop Evans Farm in McLean. Much to the consternation of neighbors and others in McLean, town houses are going up on the 24-acre site.

Not all of the supervisors support the idea of changing the approval process.

Supervisor Elaine N. McConnell (R-Springfield) said she worries that changes could slow growth by imposing further regulations and could send a message that Fairfax County no longer wants to grow. "I don't want to stop people from the use of the land they have paid their taxes on," she said.

Supervisors also said yesterday that they will prepare a database of all the vacant and underused parcels of land in the county that could still be developed.

In other action yesterday, Supervisor Robert B. Dix Jr. (R-Hunter Mill) made his first public comments since being defeated at the polls Nov. 2. Democrat Catherine M. Hudgins, a former aide to Board of Supervisors Chairman Katherine K. Hanley (D), defeated Dix and will become the Hunter Mill supervisor next year.

From the dais, where he has sat for eight years, Dix said: "I want to congratulate all of the members of the board who were reelected. It is obviously disappointing to me that I will not be joining you."

CAPTION: Supervisor Elaine N. McConnell is concerned about the effect of changes in the approval process on development. The changes are intended to reduce conflicts between owners of older and newer homes.