Other public officials have also weighed in. Peter Koo, a Democratic city councilman whose district includes Queensboro Hill, held a news conference on 56th Road last year criticizing the new construction and urging property owners, in the absence of new zoning designations, not to overbuild.

It is a complicated position for Mr. Koo, an immigrant from Hong Kong. Many of the neighborhood’s residents and a majority of those property owners who have replaced the rowhouses with bigger homes are Chinese immigrants. Some within his Chinese constituency have accused him of disloyalty.

“Where will our parents live when they come over from China?” asked Lin Xin, an employee with a contracting firm that had been involved in several of the projects in Queensboro Hill. “Why do you think we work so hard? Why do we scrimp and save? This is why. We want to be reunited with our families. We want to sit around the same table together.”

Those pushing to limit the expansion of the single-family homes may also find themselves at cross-purposes with the efforts of Mayor Bill de Blasio, a Democrat, to increase affordable housing.

“I can only hope that the mayor’s push for affordable housing can save these great Queens communities, but I fear the opposite will happen as the administration prioritizes the number of housing units rather than the quality,” Mr. Hellenbrecht said.

For her part, Ms. Lin, who immigrated to the United States from Fujian Province, China, in 1992 and had lived in the Flushing area since 1999, has found solace in the number of people who have followed her lead and built new homes on her block.

Flushing, she said, needed new housing units to serve the growing population, which included immigrants. At least half the rowhouse owners on her block have told her they like what she has done with her property and intend to do the same. And she pointed out that property values along the block have sharply increased in the past two years, a rise she partly attributes to the building potential she demonstrated.