Section 24(1) in New Town Kolkata Planning Area (Building) Rules, 2014
(1)Every plot on which erection of building will be undertaken shall be provided with a principal use or joint principal use.Note: A joint principal use in this context shall be a combination of any two permissible principal uses which together shall be covering at least 75% of the total use and each of them shall be covering at least thirty percent of the total floor area of the building in a plot.
