For Kate A. Bauer and Eric N. Lindblom, many months of feeling "stuck and trapped and frustrated" by the requirements of the Montgomery County Historic Preservation Commission appear to have come to an end.

At a three-hour hearing Wednesday night, the commission approved the couple's application to replace many of the windows in their circa 1914 house, part of the Takoma Park historic district.

At yesterday's close of business, uncertainty remained over the final wording of a clarification intended to explain the commission's decision. Even so, Lindblom and commission Chairman Julia O'Malley said they believed a mutually agreeable outcome was within reach.

Lindblom and Bauer have wanted to replace the windows since they began living in the house in 1998. The windows, they discovered, were a major source of lead-rich paint dust. The commission, which must approve changes to the exterior of some 3,000 historic properties in the county, repeatedly instructed the couple to find ways to remove the lead without altering the windows.

The couple's two daughters, 4 and 6, have less than 2.5 micrograms per deciliter of lead in their blood, well under the Centers for Disease Control and Prevention's "level of concern" of 10 micrograms per deciliter. But recent research shows that "blood lead concentrations, even those below 10 micrograms per deciliter, are inversely associated with children's IQ scores at three and five years of age," according to an April 2003 article in the New England Journal of Medicine.

Commission staff interviewed Richard L. Canfield, principal author of the article, and reported to the commission: "For levels below about five micrograms per deciliter there is evidence of small but measurable effects on cognitive function in children. According to Dr. Canfield, there is insufficient evidence to conclude that there are measurable effects below about 2.5 micrograms per deciliter but the existing evidence is suggestive."

The case has drawn the involvement of members of the County Council, who have said the commission may not be placing enough emphasis on health concerns in carrying out its mandate to preserve evidence of the county's history.

In closing Wednesday's hearing, O'Malley said she and other members of the nine-member commission were "insulted by the implication that we would not place children's health above preservation issues . . . and [by those who would] not trust us to come to an appropriate decision."

Some preservationists who spoke at the hearing insisted there need be no conflict between health concerns and preservation.

Elizabeth Perry Kapsch of the nonprofit Historic Medley District Inc. in Poolesville urged rejection of the application, saying that "hysterical fear of paint chips does not protect children, nor does destruction of historic materials."

She recommended abatement methods and suggested that parents of young children consider moving to neighborhoods built after 1978, when lead was banned from construction materials.

Bauer said yesterday that she was stunned by such comments. "What a thing to say," she said. "If you don't agree with the rules, move?"

Richard Brand of the Maryland Historical Trust told the commission that lead paint is "the 600-pound gorilla. . . . You can't ignore it." He added: "I don't want to say there are risks involved in owning an older home, but there are."

Commission staff members had recommended denial, in part because of the precedent the case might set. Windows are considered an integral part of a house's structure, and preservationists have not wanted to see homeowners using lead paint as a justification to replace them.

"I see this as being the evaluation of a single application for a historic area work permit," commission member David Rotenstein said. "I don't see it as setting historic preservation policy."

One speaker said she had reduced lead levels in her own body by eating spinach. "This flippant comment about being able to reduce lead levels by eating broccoli just makes me sick," Lindblom told the commissioners, mistaking the vegetable but not the point.

The couple had to do some horse-trading at the hearing, agreeing to one commissioner's suggestion that they not replace two prominent windows at the front of the house.

Kate A. Bauer and Eric N. Lindblom have been seeking permission to replace this and other old windows.