I don’t have any authentic figures on unsafe structures in Delhi or in India. But I know for sure majority of the structures standing at present are not safe. What is meaning of safety? Is it a relative term? Safe by what standards. Can a structure standing and in service for the last 20 years be termed as unsafe? If we desire we can debate on this issue for hours without any conclusion. In engineering terminology a structure can be termed as safe if it meets the requirements of National building Code of India and other BIS standards. If not then a structure is unsafe whether it standing for 20 or 50 years or more. BIS codes do gets revised time to time. At any moment of time a structure has to pass the test of latest code. It means if a structure was safe prior to the revision of code it may become unsafe after the revision. It seems funny but this is the fact. If this can happen with structures which have been designed and constructed according to the provisions of NBC under strict quality control then what to talk about majority of un-engineered structures.
Many structures don’t need an engineer to certify that structures are unsafe because their condition is so pathetic that any sensible person can make out that it is unsafe. But most other structures will need an experienced engineer for technical audit. There are systems & procedures to do it. Even it many cases structures can be repaired,rehabilitated or retrofitted. There are several cases where it is advisable to rebuild the structures. But it is not that easy to implement.The problem is very complex in nature. It involves identification of unsafe structures , ,making people aware about it, persuading (or forcing ) them to get it strengthened, getting trained persons to do it, necessary bye-laws & govt notifications.
In my view it should be declared a national problem and must be tackled in that spirit only. Unsafe structures may be more dangerous than a terror attack. Even a single mishap kills several hundred people. We have already witnessed Gujarat earthquake. We need a clear government policy and strong will on the part of government. But I wonder , After all these efforts can we say our structures are safe forever. Just a random thought.