A safety audit of under-construction buildings began on Tuesday, with inspection teams verifying whether developers had obtained all mandatory approvals and carried out the required quality tests during construction.
The teams checked whether structural engineers and architects were regularly supervising the work, whether periodic concrete cube tests had been conducted, and whether the quality of steel reinforcement and the grade of concrete had been tested.
The audit teams comprise engineers from the Kolkata Municipal Corporation (KMC), the state Public Works Department (PWD), the Kolkata Metropolitan Development Authority (KMDA), power utilities CESC and WBSEDCL, the fire services and the police.
They also inspected whether construction workers had access to safe and adequate lodging facilities at the sites.
A Metro team accompanied one of the inspection teams on Tuesday during its visit to an under-construction building on Lenin Sarani.
Armed with a detailed checklist, the engineers and officials inspected each site, ticking off items that met the required standards. If a document or test report was unavailable, they marked it as "not available" or used a cross to indicate non-compliance.
The teams sought signed copies of key documents, including reports on structural safety and quality control. They also checked whether developers had conducted independent third-party tests of the concrete instead of relying solely on suppliers' reports. Soil test reports were also examined.
Officials photographed the signed documents on their mobile phones as part of the inspection record.
The Kolkata Municipal Corporation (KMC), which has formed 16 audit teams for the city's 16 boroughs, deployed them across Calcutta on Tuesday. The teams submitted their inspection reports by the end of the day.
"We have been provided with a detailed checklist where 63 points are mentioned. We are asking the empanelled structural engineer of the under-construction building to remain present during our visit," said a KMC official.
A police officer accompanying the audit team at the Lenin Sarani site asked the developer's representative whether a copy of the approved building plan had been submitted to the local police station and whether security guards had been deployed round the clock at the construction site.
“An under-construction site has trenches and building materials. If it is left unguarded, an outsider could enter and fall into a trench, leading to a serious accident,” the police officer said.
He added that having a copy of the approved building plan with the local police helps officers verify whether a project has the approval from the KMC.
The officer said all under-construction buildings, irrespective of their height, must submit a copy of the approved building plan to the local police station before work begins.
The safety audits were ordered after the state government imposed a ban on the construction of all residential buildings of G+5 (six storeys) and above and commercial buildings and until July 31. The move followed the collapse of an under-construction warehouse in Garden Reach that killed 16 people.
The ban applies to Calcutta, New Town, Bidhannagar, Rajarhat, Sonarpur-Rajpur, Pujali, Maheshtala, Budge Budge, Baranagar, South Dum Dum, Kamarhati, parts of Bally, parts of the Howrah Municipal Corporation area and the Bishnupur rural area near Joka.
Rain prevented audit teams from physically inspecting certain structural elements, including foundations, sheet piling and retaining walls, at some sites. Those locations may have to be revisited.
The Bidhannagar Municipal Corporation (BMC) has constituted six safety audit teams, one for each of its six boroughs, while the New Town Kolkata Development Authority (NKDA) has formed three teams to inspect construction sites across New Town's three action areas.
"We have identified 61 under-construction buildings in the BMC area and 51 in New Town for inspection," an official said.
The teams will submit their reports to a technical sub-committee comprising the engineer-in-chief of the PWD and a professor from IIT Kharagpur. The sub-committee will assess the findings and recommend whether construction can resume or whether remedial measures are required.
The recommendations will then be placed before a high-level committee of senior government officials, which will take the final call.