In West Brandywine, Aus Marburger began canvassing neighbors after attending an August hearing on a proposed Toll Bros. development of about 115 acres near Hibernia Road. The proposal would convert the property to an age-restricted community with roughly 230 homes. Marburger and other residents formed Friends of Brandywine Farms, raised money and hired an attorney to oppose the plan.

At the hearing, residents raised concerns about added pressure on medical services after Brandywine Hospital closed, as well as potential effects on wooded and wetland areas. A September hearing was continued until Monday as the township considers the proposal.

The organizing comes as Chester County has experienced some of Pennsylvania’s strongest population growth. In 2024, multifamily and apartment construction accounted for about half of the county’s housing stock, according to the county planning commission. At the same time, county and municipal officials have invested in preserving open space; the county has more preserved private land than any other county in the nine-county Philadelphia region, officials say.

Community opposition has also focused on data centers. Residents in East Whiteland formed a group and recently retained an attorney to challenge an approved facility. In other communities, residents have used social media to share information and encourage turnout at public meetings; organizing helped stop a proposed data center in North Coventry before construction began.

Matthew Edmond, executive director of the Chester County Planning Commission, said development proposals can become major local flashpoints because they alter the landscape. Public engagement, he said, is part of the county’s civic culture.

Neighbors point to the preservation of 204-acre Crebilly Farm in Westtown as an example of what sustained organizing can achieve. Elizabeth Moro, who founded Neighbors for Crebilly LLC with her husband, said the group’s effort to stop a Toll Bros. project took years and required learning the legal and planning process as they went. Their legal bill was about $20,000, even with some work donated.

For the Moros, the expense was justified by the prospect of losing a valued landscape permanently. “Once it’s gone, we’re not going to get it back,” Moro said.

That campaign offered a model to residents near a proposed development at Lionville Station Road in Uwchlan Township. The current plan would place 492 age-restricted homes, about 100 acres of open space and a swimming facility on 228 acres owned by the Downingtown Area School District. The pool could serve the school’s swim team and the public. Earlier proposals for the property included an industrial warehouse.

Neighbors raised about $30,000 for legal help when a second warehouse was proposed nearby. After residents and the developer spoke, the developer withdrew that proposal, resident David Fertell said. The school district, which wanted to sell the land, later pursued a housing plan that responded to neighbors’ preferences. The township’s board of supervisors has until November to decide whether to approve a zoning amendment and the plan.

Fertell said organizing took time away from work and family, but he hopes supervisors approve the current proposal.

Chase Englund, founder of the Pennsylvania Small Enterprise Foundation, said residents often rally around concrete concerns such as traffic, noise, safety and a project’s appearance. Developers, by contrast, may have a harder time making a compelling case for broader economic benefits, he said. Englund also warned that extensive opposition and legal costs can weigh more heavily on smaller developers than on companies with deeper resources.

Edmond said local development disputes are likely to continue as available land declines. For residents organizing around farms, housing and data centers, the immediate question is whether sustained public pressure can shape what gets built—and what remains open.