Boston’s decision to restart construction comes as the number of infections, hospitalizations and deaths from COVID-19 appears finally to have peaked after weeks of increasingly grim daily tallies.

Frank Callahan, president of the Massachusetts Building Trades Council, which represents 75,000 workers across the state, praised the decision, noting the incremental nature of the relaunch of construction in Boston is needed given the still large level of uncertainty surrounding the coronavirus epidemic. “Like we have been saying all along, we want to get back to work as quickly as possible, with the caveat being that it has to be safe,” Callahan said, adding the coronavirus curve “looks like it is flattening.”

On May 18, city officials will allow work to resume on hospitals, public schools, and small residential projects involving three units or less, as well as road and utility work and outdoor work on other projects that involves steel erection, the pouring of concrete foundations and roofing.

Additional types of construction, as defined under the list of essential projects laid out by Massachusetts Gov. Charlie Baker (R) and his administration, will kick off again starting a week later on May 26. State officials have allowed a much wider range of construction work to continue though the pandemic, with the exception of work on new hotels and office towers.

“This incremental approach will provide the time necessary to allow complex, large-scale development an opportunity to educate their workforce, remobilize safely, and implement their site-specific safety plan,” Patrick Brophy, chief of operations in the mayor’s office, wrote in a letter to contractors and union officials.

Boston's construction restart plan kicked off May 5 with a letter from city officials to contractors and union officials notifying them that sites could begin to be prepped for workers to return. Boston Mayor Martin J. Walsh, a former top trade union official himself, also briefed construction union leaders on a Zoom call that same day.

Under safety measures laid out in advance last week by Boston officials, contractors looking to restart projects must have submitted approved safety plans and signed affidavits pledging to adhere to social distancing and other virus prevention measures.

Contractors must provide hand washing stations equipped with warm water and soap as well as a range of protective gear for their workers. The list includes facial coverings or masks, eye protection, face shields, gloves and Tyvek suits.

In reviewing safety plans submitted by contractors, city officials have said they are not only looking for measures like temperature checks of workers as they arrive, but also plans to ask workers “probing questions” related to their health, such as whether they feel sick, have been coughing or experiencing other potential COVID-19 symptoms.

A coronavirus testing station for the Boston construction industry will be set up at a school downtown, and staffed by Tufts Medical Center.

Boston’s decision in mid-March to shut down construction came amid an epic building boom in the city. There were 97 different active construction projects across the city before the ban went into place, for a total of more than 21 million sq ft of new or renovated residential, office and commercial space, according to the Boston Planning and Development Agency.

Trade union officials have been strong backers of the shutdown of all but emergency construction projects in Boston. However, after urging members earlier this month not to show up for work at projects in other cities and communities in Massachusetts, the painters and carpenters unions recently gave an all-clear to their members to return to their job sites.

In particular, both unions worked out agreements with contractors that involved ramped up safety and social distancing protections for workers, Callahan said.

Still, some Massachusetts construction workers appear to have sidestepped the restrictions, driving to nearby Connecticut to find work on projects there, according to the Hartford Business Journal.

While acknowledging that some union members may have been unhappy over the shutdowns, Callahan indicated he did not believe that large numbers of construction workers left the state to seek work elsewhere. “Just like the general public, there were some members that were not happy about it and wanted to go to work, but I don’t think that impacted the decision,” Callahan said.

Tamara Small, CEO of NAIOP Massachusetts, which represents project owners and developers across the state, said her organization is pleased to see Boston preparing to restart construction.

She argued Boston’s safety protocols and “ongoing monitoring and enforcement will allow for a safe return to construction.”

Small added, “This gradual reopening will allow for important housing and economic development projects to move forward. Worker health and safety has continued to be a top priority for NAIOP and its members since this began.”