The demolition of a building will mean smashing its ceilings, floors, beams and columns and not merely drilling holes that can be repaired easily, the Kolkata Municipal Corporation (KMC) has said in a notification.

Mayor Firhad Hakim had earlier asked officials to ensure demolition squads did not just drill holes in a ceiling or a floor. Developers often rebuild illegal structures if only a hole is made.

The KMC commissioner issued a circular on this last week.

Engineers and officials assigned to demolish a building will be held accountable if they do not make the structure unfit for living.

“The demolition process must be comprehensive and should not be restricted to partial damage,” the circular said.

“Load-bearing columns, pillars and beams must be removed to ensure that the structure cannot be reoccupied... all ceilings and floors must be dismantled so the building is rendered entirely non-habitable.”

Complaints about developers and owners repairing demolished portions of a building within weeks of the KMC drilling holes in it are common in the weekly phone-in programme Talk to Mayor.

The Telegraph reported in March 2024 that razed portions of a six-storey structure in Bowbazar, in a lane to the south of Medical College Kolkata, were rebuilt within two months of the first demolition.

The KMC usually drills holes, cuts square or rectangular portions of floors and sometimes demolishes parts of walls. This leaves enough room for rebuilding, said engineers and officials.

Preventing illegal construction has been a big challenge for the civic body.

KMC sources said the civic body was more worried about illegal construction where an entire building is built without any permission. In some cases, the owner or the developer takes permission for a certain number of floors but ends up adding several more without the KMC’s permission.

The circular said “protective gear” should be used by all involved in demolition work, “trained personnel” should be deployed and “safety nets” should be hung around the building being pulled down.

A KMC engineer said that while the decision was good, the civic body required more equipment and personnel to simultaneously carry out full demolitions of many structures. “If we have to carry out demolition work at the same pace as well as raze entire structures, we need more equipment and human resources.”

“In the past year, we have demolished over 500 illegal structures. There are only four demolition squads for the city. Pulling down an illegal building in a densely populated neighbourhood may take months,” said the engineer.