(3)If no such undertaking as is referred to in sub-section (2) is given, or if, in a case where any such undertaking has been given, the works of improvement to which the undertaking relates are not carried out within the specified period or the building is used in contravention of the undertaking, the Chief Municipal Officer shall forthwith make an order of demolition of the building requiring that the building shall be vacated within a period to be specified in the order, not being less than thirty days from the date of the order, and demolished within six weeks on the expiration of that period.
