Any building which has been condemned and placarded as a dangerous building by the Building Inspector shall be vacated within a reasonable time as stated in the notice provided for in § 151.04. No owner, lessee or occupant shall rent to any person for human habitation, and no person shall occupy any building or structure which has been condemned and placarded by the Building Inspector after the date on which said Building Inspector has required the affected building or structure to be vacated. No building or structure which has been condemned and placarded as a dangerous building shall again be used or occupied until written approval is secured from and such placard removed by the Building Inspector.
(`89 Code, § 21.050)