If workers are released from construction sites for a month, they may leave for other states in search of work. If they are retained without work, the cost burden on developers would be too high to absorb.

Developers involved in large residential projects across Calcutta and its surrounding areas, including New Town and the southern fringes, said they were worried about financial losses after chief minister Suvendu Adhikari clarified on Friday that the ban on construction till July 31 — following the Garden Reach warehouse collapse — applies to residential buildings of G+5 (six storeys) and above as well as commercial structures. The restriction has also been extended to South Dum Dum, Baranagar and Kamarhati municipalities.

However, several promoters working on buildings below G+5 said they were relieved by the clarification and would resume work.

But developers handling highrises were concerned about losses.

A developer constructing a highrise off EM Bypass in Kasba said work on a 15-storey residential building has been halted. “We have requested all workmen to wait for a couple of days. We have a labour colony near the site where they are staying and we are providing meals. If they want to leave, we cannot force them to stay back,” he said.

Suvendu said the administrator of Kolkata Municipal Corporation would request real estate developers to provide meals to workers whose projects have been put on hold till July 31. “We will not issue any official order, but this should be done on humanitarian grounds,” he said.

Officials in real estate companies said they were concerned about how quickly labour could be mobilised once the ban is lifted. “Many labourers may move to other states. They are skilled workers who cannot easily switch to other jobs. If they leave, they may not return when work resumes here. This could be a major obstacle for projects,” said one official.

“If a team had 10 labourers and only five return, we will have to hire five new people. The new team will take time to gel and work as a unit. The earlier group was already familiar with the drawings and site conditions. Now half the workforce will need time to understand the plan again, slowing progress after work resumes,” he added.

Another developer said retaining labour on-site with wages would sharply increase costs. “A large project employs between 500 and 1,100 labourers, depending on scale. Daily labour cost ranges from ₹1,500 to ₹2,000 per worker on average. It will be difficult for builders to absorb such losses,” he said.

The developer also pointed to risks in ongoing basement and foundation work. “If construction is stopped, adjoining structures may face danger. There can be water seepage, loose wiring and other issues,” he said, adding that authorities may not have the personnel to inspect all sites within such a short period.

A developer whose G+3 project was underway said work was halted on Friday. “I asked police and they said to stop work. After the chief minister’s announcement, I will resume from Saturday,” he said.

A senior official of Credai (Confederation of Real Estate Developers’ Associations of India) said the ban was justified from a safety perspective. “If a new SOP is introduced, that is also welcome. Organised developers usually follow protocols and plans. We will be able to win the confidence of the authorities,” he said.