Section 142(2) in Kolkata Municipal Corporation Building Rules, 2009
(2)The relaxations under sub-rule (1) above will be available only when the existing building which is to be demolished meets either of the following criteria:(a)The building is more than 50 years and is partly or fully occupied by tenants, or(b)the building which is upto 50 years old and declared unfit for human habitation by the appropriate authority, and when tenants demand, and are assured of equivalent amount of renewed space, post construction.Explanation - for the purpose of this sub - clause, the appropriate authority shall be such as may be decided by the State Government.
