Andrew Berman, the executive director of the Greenwich Village Society for Historic Preservation, a nonprofit advocacy group, called the online map “a useful and long-overdue tool.” He said that his group has become increasingly concerned about the rash of development in Greenwich Village, the East Village and NoHo. It is frustrating to try to find out more details about specific projects through the buildings department’s clunky databases because information is hard to access, incomplete or missing altogether, he said.

Still, Mr. Berman noted that the map alone was not enough, and that other measures were needed to tighten the city’s oversight of the building boom, including more enforcement of safety, zoning and construction regulations.

“It’s great to have statistics,” he said. “But the single most important thing the buildings department needs to do is enforce regulations that ensure that a building is done safely and conforms with what’s allowed to be built on that site.”

The online map is part of a $60 million digital initiative by the agency that began in 2015 and has offered an impressive level of detail about the city’s buildings. Other online maps display every elevator and escalator in every building, and track all the scaffolding erected around buildings under repair or construction.

Such efforts have drawn support not only from community groups but also industry leaders, including the Real Estate Board of New York, a powerful trade association of the city’s largest building owners and landlords. “We applaud the effort to increase digital innovation that will lead to a buildings department that is more accessible to the public and more responsive to the needs of the private sector,” said John H. Banks, the organization’s president. “These digital improvements will increase transparency and public awareness of the economic activity, jobs and tax revenue generated at construction sites across the city.”

Mr. Chandler said the data has also been used behind the scenes to assess and improve the department’s operations. For instance, a data analysis showed that in October 2017, the department took more than 15 days to process certificates of occupancy for 161 new buildings. Building officials followed up by streamlining the process and tightening oversight of staff. Last month, only eight buildings took that long.

Buildings officials said the new construction map will be expanded based on feedback from users and as more comprehensive data becomes available. The map will be updated daily — offering a real-time advantage over analyst and industry reports.