When Lalita Park, along with several other colonies in east Delhi, was regularised in 1983, the government took all factors such as layout plans and civic facilities into account.
But the policy makers forgot to take one of the most important aspects of a building into account - its structural safety.
The 1977 policy of the government, under which the unauthorised Lalita Park colony was regularised, did not take into account the structural safety of the buildings.
Sources said the structural safety of the building is still not a criteria in the 2007 policy of the government under which 1,639 colonies may be regularised soon.
The Delhi government is trying to save its neck. "We only regularise the colony and not the structure," said AK Walia, urban development minister of Delhi government.
The government claimed that structural safety can only be checked after the colony has been handed over to the Municipal Corporation of Delhi (MCD) for maintenance.
"The fact that they are called unauthorised in itself means that construction there has been carried out without any approval. After we have regularised the colony, the MCD has to ensure that all construction is carried out after sanctioning of building plans. They are responsible for checking illegal constructions," he added.
According to experts, the structural design of any building depends upon the kind of usage they are put into - residential or commercial. The second important consideration is the foundation. Both of which were ignored in buildings such as those in Lalita Park area.
The MCD officials claim unstable structures are already there when they the regularised colony is handed over to them. "We can only sanction plans if someone comes to us. The buildings already have four storeys when they come to us," said a senior MCD official.
"If the buildings are regularised without checking for structural stability, they become potential dangers. Before regularisation, it should be checked whether a structurally weak building can be strengthened. If not, it should be razed," said RC Kehar, former chairman, National Buildings Construction Corporation.
Officials said government should stop supply of water and electricity to the unauthorised colonies to prevent them from mushrooming.