The rapid adjustments, while not universal across all job sites, have been embraced in an industry that prizes safety but has notoriously dirty job sites, often with few portable restrooms and no running water. Crews often share tools and work side by side.

The changes were enacted only after construction workers spoke out in mid-March over workplace conditions, including a lack of protective gear and a reluctance to enforce health measures like social distancing.

A month later, roughly 85 percent of the construction sites in New York City that were operating before the pandemic have come to a halt after the state revised its order and deemed them nonessential. But every day hundreds of job sites have opened back up as developers, contractors and labor groups have lobbied officials to get them running again.

Roughly 5,200 construction projects were operating again as of Tuesday, from the Spiral office tower at Hudson Yards on the Far West Side to One Vanderbilt near Grand Central Terminal and home renovations in Far Rockaway, Queens.

Governor Andrew M. Cuomo announced recently that the construction industry would be among the first categories of “low-risk” businesses allowed to return to normal as part of the state’s phased reopening scheduled to start as soon as mid-May.

But some workers are dubious that work could soon resume safely.

“There is no social distancing on a construction site,” said a carpenter who was told that his job site, a new hotel in Midtown Manhattan, would reopen on Wednesday.

When the site reopens, it will have a turnstile to control who enters, additional hand-washing areas and running water, the contractor told the site’s workers, according to the carpenter, who requested anonymity because he did not have permission to speak with the news media.