All commercial buildings in Delhi, including hotels, shopping malls, multiplexes and private office complexes, where the average footfall is 1,000 or more a day, may soon have to get special ‘‘security’’ clearance from the government before they get the occupation certificate. The clearance to the buildings — both existing and upcoming ones — will depend upon their adhering to certain security norms, including setting up access control systems, CCTVs and other features. The purpose is to take care of security loopholes so that any big commercial or private office complex can be better prepared to for terrorist attacks like the ones that happened at the Taj and Oberoi in Mumbai last year. The norms will be finalized by the home ministry in consultation with various agencies and town planners. Once it is successfully implemented in Delhi, the model will be replicated in other metros — Mumbai, Kolkata, Hyderabad, Chennai, Ahmedabad and Bangalore.