Residents of Massachusetts Avenue Heights, the neighborhood with the most expensive homes in the city, say they've found a way to stop developers from leveling the area's rolling hills and wooded lots.

They've fashioned their own zoning law.

They want their neighborhood identified as a special zoning district where developers would be prohibited from cutting down old trees or changing the terrain of any vacant parcel without city permission. It would not prevent individual homeowners from doing either of these things.

If approved by the Zoning Commission, where developers are expected to wage a tough fight, the district would be the first of its kind in the city.

"It would slow down the bulldozers and chain saws," said Laurence Aurbach, a neighborhood leader. "The topography and trees are the main heritage of this neighborhood. We are trying to protect that heritage."

But some developers say the proposal is unfair because it exempts homeowners from its strict provisions while effectively barring some landowners from building anything on their vacant property.

Nestled between Rock Creek Park and the Naval Observatory, Massachusetts Avenue Heights is a lush, hilly neighborhood of grand embassies and elegant homes. The average house there costs $1.3 million.

It's a neighborhood of financiers, stockbrokers, architects, politicians, builders. TV talk show host John McLaughlin lives here. So do former senator and Reagan administration chief of staff Howard Baker, and USA Today Publisher Cathleen Black.

And, of course, lawyers.

In the six families that first organized against developers, there are eight lawyers, said Linda Sher, a labor lawyer and a president of the newly formed Woodland-Normanstone Neighborhood Associaton.

Unlike the streets in the rest of the city, the roads here twist and curve. In 1910, Congress exempted the neighborhood from Pierre L'Enfant's gridded street pattern in part because the steep slopes made it too expensive for developers to subdivide their parcels into standard city blocks.

But developers are running out of land and some have begun leveling some of those steep slopes to build big houses up against each other on tiny, treeless yards.

"Tract mansions," Sher calls them. Houses not in keeping with the "country feeling" of the neighborhood, complained resident Sandra McElwaine.

The neighbors credit developer Lawrence Brandt for getting them organized. About 18 months ago, Brandt leveled a wooded hill overlooking Rock Creek Park to build seven brick mansions. A battle ensued between neighbors and Brandt, and in the end, the neighbors lost.

Last fall, Sher and Aurbach organized a new neighborhood association and just about every homeowner in the area joined, Sher said.

They then drafted their proposal to make the area a special "overlay district" where developers would be required to get city permission to destroy trees more than 24 inches in circumference or alter topography. In addition, all side yards of new houses built there would have to be at least 16 feet wide.

The proposal, which is set for a hearing on June 18, is similar to zoning tools used in Montgomery County and California, Sher said.

In February, after developer Michael Minkoff cut down a strand of hardwoods on Woodland Drive NW to make room for new houses, the city put the overlay district into effect on an emergency basis, pending the outcome of the Zoning Commission decision.

But Brandt maintains that the proposal is unfair because it allows residents to cut down trees and change their terrain to build additions, but prohibits owners of vacant land from doing the same to build new houses.

The requirement of 16-foot side yards is ridiculous, he said, because owners of some lots could build houses only 18 feet wide.

McElwaine said the proposal will stop "appalling development."

As she sees it, if the commission approves, other neighborhoods could do the same thing to help preserve their natural landscapes.

"No one should be allowed to muck up a whole track of land," she said.